diff --git a/hyracks-examples/btree-example/btreeapp/pom.xml b/hyracks-examples/btree-example/btreeapp/pom.xml
index e3f0590..737eaa0 100644
--- a/hyracks-examples/btree-example/btreeapp/pom.xml
+++ b/hyracks-examples/btree-example/btreeapp/pom.xml
@@ -11,6 +11,35 @@
   </parent>
 
   <build>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <groupId>org.eclipse.m2e</groupId>
+          <artifactId>lifecycle-mapping</artifactId>
+          <version>1.0.0</version>
+          <configuration>
+            <lifecycleMappingMetadata>
+              <pluginExecutions>
+                <pluginExecution>
+                  <pluginExecutionFilter>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-dependency-plugin</artifactId>
+                    <versionRange>[1.0.0,)</versionRange>
+                    <goals>
+                      <goal>copy-dependencies</goal>
+                    </goals>
+                  </pluginExecutionFilter>
+                  <action>
+                    <ignore />
+                  </action>
+                </pluginExecution>
+              </pluginExecutions>
+            </lifecycleMappingMetadata>
+          </configuration>
+        </plugin>
+      </plugins>
+	</pluginManagement>
+  
     <plugins>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
diff --git a/hyracks-examples/hadoop-compat-example/hadoopcompatapp/pom.xml b/hyracks-examples/hadoop-compat-example/hadoopcompatapp/pom.xml
index 0d3ab7f..5fc56a1 100644
--- a/hyracks-examples/hadoop-compat-example/hadoopcompatapp/pom.xml
+++ b/hyracks-examples/hadoop-compat-example/hadoopcompatapp/pom.xml
@@ -11,6 +11,35 @@
   </parent>
 
   <build>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <groupId>org.eclipse.m2e</groupId>
+          <artifactId>lifecycle-mapping</artifactId>
+          <version>1.0.0</version>
+          <configuration>
+            <lifecycleMappingMetadata>
+              <pluginExecutions>
+                <pluginExecution>
+                  <pluginExecutionFilter>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-dependency-plugin</artifactId>
+                    <versionRange>[1.0.0,)</versionRange>
+                    <goals>
+                      <goal>copy-dependencies</goal>
+                    </goals>
+                  </pluginExecutionFilter>
+                  <action>
+                    <ignore />
+                  </action>
+                </pluginExecution>
+              </pluginExecutions>
+            </lifecycleMappingMetadata>
+          </configuration>
+        </plugin>
+      </plugins>
+	</pluginManagement>
+  
     <plugins>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
diff --git a/hyracks-examples/text-example/textapp/pom.xml b/hyracks-examples/text-example/textapp/pom.xml
index 269ef2b..dd1b5ae 100644
--- a/hyracks-examples/text-example/textapp/pom.xml
+++ b/hyracks-examples/text-example/textapp/pom.xml
@@ -11,6 +11,35 @@
   </parent>
 
   <build>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <groupId>org.eclipse.m2e</groupId>
+          <artifactId>lifecycle-mapping</artifactId>
+          <version>1.0.0</version>
+          <configuration>
+            <lifecycleMappingMetadata>
+              <pluginExecutions>
+                <pluginExecution>
+                  <pluginExecutionFilter>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-dependency-plugin</artifactId>
+                    <versionRange>[1.0.0,)</versionRange>
+                    <goals>
+                      <goal>copy-dependencies</goal>
+                    </goals>
+                  </pluginExecutionFilter>
+                  <action>
+                    <ignore />
+                  </action>
+                </pluginExecution>
+              </pluginExecutions>
+            </lifecycleMappingMetadata>
+          </configuration>
+        </plugin>
+      </plugins>
+	</pluginManagement>
+  
     <plugins>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
diff --git a/hyracks-examples/tpch-example/tpchapp/pom.xml b/hyracks-examples/tpch-example/tpchapp/pom.xml
index 5e11a20..3ea1e99 100644
--- a/hyracks-examples/tpch-example/tpchapp/pom.xml
+++ b/hyracks-examples/tpch-example/tpchapp/pom.xml
@@ -11,6 +11,35 @@
   </parent>
 
   <build>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <groupId>org.eclipse.m2e</groupId>
+          <artifactId>lifecycle-mapping</artifactId>
+          <version>1.0.0</version>
+          <configuration>
+            <lifecycleMappingMetadata>
+              <pluginExecutions>
+                <pluginExecution>
+                  <pluginExecutionFilter>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-dependency-plugin</artifactId>
+                    <versionRange>[1.0.0,)</versionRange>
+                    <goals>
+                      <goal>copy-dependencies</goal>
+                    </goals>
+                  </pluginExecutionFilter>
+                  <action>
+                    <ignore />
+                  </action>
+                </pluginExecution>
+              </pluginExecutions>
+            </lifecycleMappingMetadata>
+          </configuration>
+        </plugin>
+      </plugins>
+	</pluginManagement>
+  
     <plugins>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrame.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrame.java
index bd4947c..f74e2ee 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrame.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrame.java
@@ -30,6 +30,7 @@
 import edu.uci.ics.hyracks.storage.am.btree.api.IFrameCompressor;
 import edu.uci.ics.hyracks.storage.am.btree.api.IPrefixSlotManager;
 import edu.uci.ics.hyracks.storage.am.btree.compressors.FieldPrefixCompressor;
+import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.FieldPrefixPrefixTupleReference;
 import edu.uci.ics.hyracks.storage.am.btree.impls.FieldPrefixSlotManager;
@@ -168,12 +169,12 @@
             slotManager.setSlot(sortedTupleOffs.get(i).slotOff, slotManager.encodeSlotFields(prefixSlotNum, freeSpace));
             freeSpace += tupleLength;
         }
-        
+
         buf.putInt(freeSpaceOff, freeSpace);
         int totalFreeSpace = buf.capacity() - buf.getInt(freeSpaceOff)
                 - ((buf.getInt(tupleCountOff) + buf.getInt(prefixTupleCountOff)) * slotManager.getSlotSize());
         buf.putInt(totalFreeSpaceOff, totalFreeSpace);
-        
+
         return false;
     }
 
@@ -192,9 +193,8 @@
                 frameTuple.setFieldCount(cmp.getFieldCount());
                 frameTuple.resetByTupleIndex(this, tupleIndex);
 
-                int comparison = cmp.fieldRangeCompare(tuple, frameTuple, cmp.getKeyFieldCount() - 1, cmp
-                        .getFieldCount()
-                        - cmp.getKeyFieldCount());
+                int comparison = cmp.fieldRangeCompare(tuple, frameTuple, cmp.getKeyFieldCount() - 1,
+                        cmp.getFieldCount() - cmp.getKeyFieldCount());
                 if (comparison != 0) {
                     throw new BTreeException("Cannot delete tuple. Byte-by-byte comparison failed to prove equality.");
                 }
@@ -233,16 +233,15 @@
 
         int bytesRequired = tupleWriter.bytesRequired(tuple);
 
-        // see if the tuple would fit uncompressed
+        // See if the tuple would fit uncompressed.
         if (bytesRequired + slotManager.getSlotSize() <= freeContiguous)
             return FrameOpSpaceStatus.SUFFICIENT_CONTIGUOUS_SPACE;
 
-        // see if tuple would fit into remaining space after compaction
+        // See if tuple would fit into remaining space after compaction.
         if (bytesRequired + slotManager.getSlotSize() <= buf.getInt(totalFreeSpaceOff))
             return FrameOpSpaceStatus.SUFFICIENT_SPACE;
 
-        // see if the tuple matches a prefix and will fit after truncating the
-        // prefix
+        // See if the tuple matches a prefix and will fit after truncating the prefix.
         int prefixSlotNum = slotManager.findPrefix(tuple, framePrefixTuple, cmp);
         if (prefixSlotNum != FieldPrefixSlotManager.TUPLE_UNCOMPRESSED) {
             int prefixSlotOff = slotManager.getPrefixSlotOff(prefixSlotNum);
@@ -259,7 +258,7 @@
     }
 
     @Override
-    public FrameOpSpaceStatus hasSpaceUpdate(int rid, ITupleReference tuple, MultiComparator cmp) {
+    public FrameOpSpaceStatus hasSpaceUpdate(ITupleReference tuple, int oldTupleIndex, MultiComparator cmp) {
         // TODO Auto-generated method stub
         return FrameOpSpaceStatus.INSUFFICIENT_SPACE;
     }
@@ -292,13 +291,26 @@
     }
 
     @Override
-    public int findTupleIndex(ITupleReference tuple, MultiComparator cmp) throws Exception {
-    	return slotManager.findSlot(tuple, frameTuple, framePrefixTuple, cmp, FindTupleMode.FTM_INCLUSIVE,
-    			FindTupleNoExactMatchPolicy.FTP_HIGHER_KEY);
+    public int findTupleIndex(ITupleReference tuple, MultiComparator cmp, boolean throwIfKeyExists) throws Exception {
+        int slot = slotManager.findSlot(tuple, frameTuple, framePrefixTuple, cmp, FindTupleMode.FTM_INCLUSIVE,
+                FindTupleNoExactMatchPolicy.FTP_HIGHER_KEY);
+        if (!throwIfKeyExists) {
+            return slot;
+        }
+        int tupleIndex = slotManager.decodeSecondSlotField(slot);
+        if (tupleIndex != FieldPrefixSlotManager.GREATEST_SLOT) {
+            frameTuple.setFieldCount(cmp.getFieldCount());
+            frameTuple.resetByTupleIndex(this, tupleIndex);
+            int comparison = cmp.fieldRangeCompare(tuple, frameTuple, 0, cmp.getKeyFieldCount());
+            if (comparison == 0) {
+                throw new BTreeDuplicateKeyException("Trying to insert duplicate key into leaf node.");
+            }
+        }
+        return slot;
     }
-    
+
     @Override
-    public void insert(ITupleReference tuple, MultiComparator cmp, int tupleIndex) throws Exception {        
+    public void insert(ITupleReference tuple, MultiComparator cmp, int tupleIndex) throws Exception {
         int slot = slotManager.insertSlot(tupleIndex, buf.getInt(freeSpaceOff));
         int prefixSlotNum = slotManager.decodeFirstSlotField(slot);
         int numPrefixFields = 0;
@@ -320,11 +332,11 @@
     }
 
     @Override
-    public void update(int rid, ITupleReference tuple) throws Exception {
+    public void update(ITupleReference newTuple, int oldTupleIndex, boolean inPlace) throws Exception {
         // TODO Auto-generated method stub
 
     }
-
+    
     @Override
     public void printHeader() {
         // TODO Auto-generated method stub
@@ -348,8 +360,8 @@
         for (int i = 0; i < tupleCount; i++) {
             frameTuple.resetByTupleIndex(this, i);
             for (int j = 0; j < cmp.getKeyFieldCount(); j++) {
-                ByteArrayInputStream inStream = new ByteArrayInputStream(frameTuple.getFieldData(j), frameTuple
-                        .getFieldStart(j), frameTuple.getFieldLength(j));
+                ByteArrayInputStream inStream = new ByteArrayInputStream(frameTuple.getFieldData(j),
+                        frameTuple.getFieldStart(j), frameTuple.getFieldLength(j));
                 DataInput dataIn = new DataInputStream(inStream);
                 Object o = fields[j].deserialize(dataIn);
                 strBuilder.append(o.toString() + " ");
@@ -386,7 +398,7 @@
     public boolean isLeaf() {
         return buf.get(levelOff) == 0;
     }
-    
+
     @Override
     public boolean isInterior() {
         return buf.get(levelOff) > 0;
@@ -461,7 +473,7 @@
         BTreeFieldPrefixNSMLeafFrame rf = (BTreeFieldPrefixNSMLeafFrame) rightFrame;
 
         frameTuple.setFieldCount(cmp.getFieldCount());
-        
+
         ByteBuffer right = rf.getBuffer();
         int tupleCount = getTupleCount();
         int prefixTupleCount = getPrefixTupleCount();
@@ -522,7 +534,7 @@
 
                     int bytesWritten = 0;
                     if (lastPrefixSlotNum != prefixSlotNum) {
-                        bytesWritten = tupleWriter.writeTuple(framePrefixTuple, right, freeSpace);
+                        bytesWritten = tupleWriter.writeTuple(framePrefixTuple, right.array(), freeSpace);
                         int newPrefixSlot = rf.slotManager
                                 .encodeSlotFields(framePrefixTuple.getFieldCount(), freeSpace);
                         int prefixSlotOff = rf.slotManager.getPrefixSlotOff(prefixSlotNum);
@@ -571,7 +583,8 @@
         rightFrame.compact(cmp);
 
         // insert last key
-        int targetTupleIndex = targetFrame.findTupleIndex(tuple, cmp);
+        // TODO: can we avoid checking for duplicates here?
+        int targetTupleIndex = targetFrame.findTupleIndex(tuple, cmp, true);
         targetFrame.insert(tuple, cmp, targetTupleIndex);
 
         // set split key to be highest value in left page
@@ -658,7 +671,7 @@
     }
 
     @Override
-	public int getPageHeaderSize() {
-		return nextLeafOff;
-	}
+    public int getPageHeaderSize() {
+        return nextLeafOff;
+    }
 }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrameFactory.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrameFactory.java
index 05b43d3..70ac13a 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrameFactory.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrameFactory.java
@@ -22,7 +22,7 @@
 public class BTreeFieldPrefixNSMLeafFrameFactory implements ITreeIndexFrameFactory {
 
     private static final long serialVersionUID = 1L;
-    private ITreeIndexTupleWriterFactory tupleWriterFactory;
+    private final ITreeIndexTupleWriterFactory tupleWriterFactory;
 
     public BTreeFieldPrefixNSMLeafFrameFactory(ITreeIndexTupleWriterFactory tupleWriterFactory) {
         this.tupleWriterFactory = tupleWriterFactory;
@@ -32,4 +32,9 @@
     public IBTreeLeafFrame createFrame() {
         return new BTreeFieldPrefixNSMLeafFrame(tupleWriterFactory.createTupleWriter());
     }
+
+    @Override
+    public ITreeIndexTupleWriterFactory getTupleWriterFactory() {
+       return tupleWriterFactory;
+    }
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMInteriorFrame.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMInteriorFrame.java
index 6025003..0d56cb0 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMInteriorFrame.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMInteriorFrame.java
@@ -26,7 +26,7 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeInteriorFrame;
-import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeException;
+import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.ISplitKey;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrame;
@@ -44,7 +44,7 @@
     private static final int rightLeafOff = smFlagOff + 1;
 
     private static final int childPtrSize = 4;
-    
+
     // private SimpleTupleReference cmpFrameTuple = new SimpleTupleReference();
     private ITreeIndexTupleReference cmpFrameTuple;
 
@@ -77,13 +77,17 @@
             return FrameOpSpaceStatus.INSUFFICIENT_SPACE;
     }
 
-    public int findTupleIndex(ITupleReference tuple, MultiComparator cmp) throws Exception {
-    	frameTuple.setFieldCount(cmp.getKeyFieldCount());
+    public int findTupleIndex(ITupleReference tuple, MultiComparator cmp, boolean throwIfKeyExists) throws Exception {
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
         int tupleIndex = slotManager.findTupleIndex(tuple, frameTuple, cmp, FindTupleMode.FTM_INCLUSIVE,
                 FindTupleNoExactMatchPolicy.FTP_HIGHER_KEY);
+        if (!throwIfKeyExists) {
+            return tupleIndex;
+        }
         int slotOff = slotManager.getSlotOff(tupleIndex);
         boolean isDuplicate = true;
 
+        // TODO: We may not need to check for duplicates in interior nodes.
         if (tupleIndex < 0)
             isDuplicate = false; // greater than all existing keys
         else {
@@ -92,45 +96,44 @@
                 isDuplicate = false;
         }
         if (isDuplicate) {
-            throw new BTreeException("Trying to insert duplicate value into interior node.");
+            throw new BTreeDuplicateKeyException("Trying to insert duplicate key into interior node.");
         }
         return tupleIndex;
     }
-    
+
     @Override
     public void insert(ITupleReference tuple, MultiComparator cmp, int tupleIndex) throws Exception {
-    	int slotOff = slotManager.insertSlot(tupleIndex, buf.getInt(freeSpaceOff));
-    	int freeSpace = buf.getInt(freeSpaceOff);
-    	int bytesWritten = tupleWriter.writeTupleFields(tuple, 0, cmp.getKeyFieldCount(), buf, freeSpace);
-    	System.arraycopy(tuple.getFieldData(cmp.getKeyFieldCount() - 1), getLeftChildPageOff(tuple, cmp), buf
-    			.array(), freeSpace + bytesWritten, childPtrSize);
-    	int tupleSize = bytesWritten + childPtrSize;
+        int slotOff = slotManager.insertSlot(tupleIndex, buf.getInt(freeSpaceOff));
+        int freeSpace = buf.getInt(freeSpaceOff);
+        int bytesWritten = tupleWriter.writeTupleFields(tuple, 0, cmp.getKeyFieldCount(), buf, freeSpace);
+        System.arraycopy(tuple.getFieldData(cmp.getKeyFieldCount() - 1), getLeftChildPageOff(tuple, cmp), buf.array(),
+                freeSpace + bytesWritten, childPtrSize);
+        int tupleSize = bytesWritten + childPtrSize;
 
-    	buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
-    	buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + tupleSize);
-    	buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) - tupleSize - slotManager.getSlotSize());
+        buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
+        buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + tupleSize);
+        buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) - tupleSize - slotManager.getSlotSize());
 
-    	// did insert into the rightmost slot?
-    	if (slotOff == slotManager.getSlotEndOff()) {
-    		System.arraycopy(tuple.getFieldData(cmp.getKeyFieldCount() - 1), getLeftChildPageOff(tuple, cmp)
-    				+ childPtrSize, buf.array(), rightLeafOff, childPtrSize);
-    	} else {
-    		// if slotOff has a right (slot-)neighbor then update its child
-    		// pointer
-    		// the only time when this is NOT the case, is when this is the
-    		// first tuple
-    		// (or when the splitkey goes into the rightmost slot but that
-    		// case was handled in the if above)
-    		if (buf.getInt(tupleCountOff) > 1) {
-    			int rightNeighborOff = slotOff - slotManager.getSlotSize();
-    			frameTuple.resetByTupleOffset(buf, slotManager.getTupleOff(rightNeighborOff));
-    			System.arraycopy(tuple.getFieldData(0), getLeftChildPageOff(tuple, cmp) + childPtrSize,
-    					buf.array(), getLeftChildPageOff(frameTuple, cmp), childPtrSize);
-    		}
-    	}
+        // did insert into the rightmost slot?
+        if (slotOff == slotManager.getSlotEndOff()) {
+            System.arraycopy(tuple.getFieldData(cmp.getKeyFieldCount() - 1), getLeftChildPageOff(tuple, cmp)
+                    + childPtrSize, buf.array(), rightLeafOff, childPtrSize);
+        } else {
+            // if slotOff has a right (slot-)neighbor then update its child
+            // pointer
+            // the only time when this is NOT the case, is when this is the
+            // first tuple
+            // (or when the splitkey goes into the rightmost slot but that
+            // case was handled in the if above)
+            if (buf.getInt(tupleCountOff) > 1) {
+                int rightNeighborOff = slotOff - slotManager.getSlotSize();
+                frameTuple.resetByTupleOffset(buf, slotManager.getTupleOff(rightNeighborOff));
+                System.arraycopy(tuple.getFieldData(0), getLeftChildPageOff(tuple, cmp) + childPtrSize, buf.array(),
+                        getLeftChildPageOff(frameTuple, cmp), childPtrSize);
+            }
+        }
     }
 
-
     @Override
     public void insertSorted(ITupleReference tuple, MultiComparator cmp) throws HyracksDataException {
         int freeSpace = buf.getInt(freeSpaceOff);
@@ -151,7 +154,7 @@
             throws Exception {
         // before doing anything check if key already exists
         frameTuple.setFieldCount(cmp.getKeyFieldCount());
-        
+
         ByteBuffer right = rightFrame.getBuffer();
         int tupleCount = buf.getInt(tupleCountOff);
 
@@ -203,9 +206,10 @@
         compact(cmp);
 
         // insert key
-        int targetTupleIndex = targetFrame.findTupleIndex(savedSplitKey.getTuple(), cmp);
+        // TODO: can we avoid checking for duplicates here?
+        int targetTupleIndex = targetFrame.findTupleIndex(savedSplitKey.getTuple(), cmp, true);
         targetFrame.insert(savedSplitKey.getTuple(), cmp, targetTupleIndex);
-        
+
         return 0;
     }
 
@@ -242,7 +246,7 @@
 
         buf.putInt(freeSpaceOff, freeSpace);
         buf.putInt(totalFreeSpaceOff, buf.capacity() - freeSpace - tupleCount * slotManager.getSlotSize());
-        
+
         return false;
     }
 
@@ -316,7 +320,7 @@
                 }
                 slotOff += slotManager.getSlotSize();
             }
-            
+
             frameTuple.resetByTupleOffset(buf, slotManager.getTupleOff(slotOff));
             int childPageOff = getLeftChildPageOff(frameTuple, srcCmp);
             return buf.getInt(childPageOff);
@@ -351,8 +355,8 @@
 
         // maintain space information
         buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) - 1);
-        buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) + keySize + childPtrSize
-                + slotManager.getSlotSize());
+        buf.putInt(totalFreeSpaceOff,
+                buf.getInt(totalFreeSpaceOff) + keySize + childPtrSize + slotManager.getSlotSize());
     }
 
     @Override
@@ -388,8 +392,10 @@
         for (int i = 0; i < tupleCount; i++) {
             int tupleOff = slotManager.getTupleOff(slotManager.getSlotOff(i));
             frameTuple.resetByTupleOffset(buf, tupleOff);
-            int intVal = getInt(buf.array(), frameTuple.getFieldStart(frameTuple.getFieldCount() - 1)
-                    + frameTuple.getFieldLength(frameTuple.getFieldCount() - 1));
+            int intVal = getInt(
+                    buf.array(),
+                    frameTuple.getFieldStart(frameTuple.getFieldCount() - 1)
+                            + frameTuple.getFieldLength(frameTuple.getFieldCount() - 1));
             ret.add(intVal);
         }
         if (!isLeaf()) {
@@ -411,8 +417,8 @@
 
         // maintain space information
         buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) - 1);
-        buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) + keySize + childPtrSize
-                + slotManager.getSlotSize());
+        buf.putInt(totalFreeSpaceOff,
+                buf.getInt(totalFreeSpaceOff) + keySize + childPtrSize + slotManager.getSlotSize());
 
         int freeSpace = buf.getInt(freeSpaceOff);
         if (freeSpace == tupleOff + keySize + childPtrSize) {
@@ -433,8 +439,8 @@
         for (int i = 0; i < tupleCount; i++) {
             frameTuple.resetByTupleIndex(this, i);
             for (int j = 0; j < cmp.getKeyFieldCount(); j++) {
-                ByteArrayInputStream inStream = new ByteArrayInputStream(frameTuple.getFieldData(j), frameTuple
-                        .getFieldStart(j), frameTuple.getFieldLength(j));
+                ByteArrayInputStream inStream = new ByteArrayInputStream(frameTuple.getFieldData(j),
+                        frameTuple.getFieldStart(j), frameTuple.getFieldLength(j));
                 DataInput dataIn = new DataInputStream(inStream);
                 Object o = fields[j].deserialize(dataIn);
                 strBuilder.append(o.toString() + " ");
@@ -444,9 +450,9 @@
         strBuilder.append("\n");
         return strBuilder.toString();
     }
-    
+
     @Override
-	public int getPageHeaderSize() {
-		return rightLeafOff;
-	}
+    public int getPageHeaderSize() {
+        return rightLeafOff;
+    }
 }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMInteriorFrameFactory.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMInteriorFrameFactory.java
index 6b30ee0..8618df8 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMInteriorFrameFactory.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMInteriorFrameFactory.java
@@ -22,7 +22,7 @@
 public class BTreeNSMInteriorFrameFactory implements ITreeIndexFrameFactory {
 
     private static final long serialVersionUID = 1L;
-    private ITreeIndexTupleWriterFactory tupleWriterFactory;
+    private final ITreeIndexTupleWriterFactory tupleWriterFactory;
 
     public BTreeNSMInteriorFrameFactory(ITreeIndexTupleWriterFactory tupleWriterFactory) {
         this.tupleWriterFactory = tupleWriterFactory;
@@ -32,4 +32,9 @@
     public IBTreeInteriorFrame createFrame() {
         return new BTreeNSMInteriorFrame(tupleWriterFactory.createTupleWriter());
     }
+
+    @Override
+    public ITreeIndexTupleWriterFactory getTupleWriterFactory() {
+        return tupleWriterFactory;
+    }
 }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrame.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrame.java
index 85fbec9..0ffc400 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrame.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrame.java
@@ -20,7 +20,7 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame;
-import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeException;
+import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.common.api.ISplitKey;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrame;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleReference;
@@ -66,42 +66,46 @@
     }
 
     @Override
-    public int findTupleIndex(ITupleReference tuple, MultiComparator cmp) throws Exception {
-    	frameTuple.setFieldCount(cmp.getFieldCount());
+    public int findTupleIndex(ITupleReference tuple, MultiComparator cmp, boolean throwIfKeyExists) throws Exception {
+        frameTuple.setFieldCount(cmp.getFieldCount());
         int tupleIndex = slotManager.findTupleIndex(tuple, frameTuple, cmp, FindTupleMode.FTM_INCLUSIVE,
                 FindTupleNoExactMatchPolicy.FTP_HIGHER_KEY);
+        if (!throwIfKeyExists) {
+            return tupleIndex;
+        }
         int slotOff = slotManager.getSlotOff(tupleIndex);
         boolean isDuplicate = true;
-
-        if (tupleIndex < 0)
-            isDuplicate = false; // greater than all existing keys
+        if (tupleIndex < 0) {
+            // Greater than all existing keys.
+            isDuplicate = false;
+        }
         else {
             frameTuple.resetByTupleOffset(buf, slotManager.getTupleOff(slotOff));
-            if (cmp.compare(tuple, frameTuple) != 0)
+            if (cmp.compare(tuple, frameTuple) != 0) {
                 isDuplicate = false;
+            }
         }
         if (isDuplicate) {
-            throw new BTreeException("Trying to insert duplicate value into leaf of unique index");
+            throw new BTreeDuplicateKeyException("Trying to insert duplicate key into leaf node.");
         }
-        
         return tupleIndex;
     }
-    
+
     @Override
-    public void insert(ITupleReference tuple, MultiComparator cmp, int tupleIndex) throws Exception {    	
-    	slotManager.insertSlot(tupleIndex, buf.getInt(freeSpaceOff));
-    	int freeSpace = buf.getInt(freeSpaceOff);
-    	int bytesWritten = tupleWriter.writeTuple(tuple, buf, freeSpace);
-    	buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
-    	buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + bytesWritten);
-    	buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) - bytesWritten - slotManager.getSlotSize());
+    public void insert(ITupleReference tuple, MultiComparator cmp, int tupleIndex) throws Exception {
+        slotManager.insertSlot(tupleIndex, buf.getInt(freeSpaceOff));
+        int freeSpace = buf.getInt(freeSpaceOff);
+        int bytesWritten = tupleWriter.writeTuple(tuple, buf.array(), freeSpace);
+        buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
+        buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + bytesWritten);
+        buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) - bytesWritten - slotManager.getSlotSize());
     }
 
     @Override
     public void insertSorted(ITupleReference tuple, MultiComparator cmp) throws HyracksDataException {
         int freeSpace = buf.getInt(freeSpaceOff);
         slotManager.insertSlot(-1, freeSpace);
-        int bytesWritten = tupleWriter.writeTuple(tuple, buf, freeSpace);
+        int bytesWritten = tupleWriter.writeTuple(tuple, buf.array(), freeSpace);
         buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
         buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + bytesWritten);
         buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) - bytesWritten - slotManager.getSlotSize());
@@ -112,7 +116,7 @@
             throws Exception {
 
         frameTuple.setFieldCount(cmp.getFieldCount());
-        
+
         ByteBuffer right = rightFrame.getBuffer();
         int tupleCount = getTupleCount();
 
@@ -149,7 +153,8 @@
         compact(cmp);
 
         // insert last key
-        int targetTupleIndex = targetFrame.findTupleIndex(tuple, cmp);
+        // TODO: can we avoid checking for duplicates here?
+        int targetTupleIndex = targetFrame.findTupleIndex(tuple, cmp, true);
         targetFrame.insert(tuple, cmp, targetTupleIndex);
 
         // set split key to be highest value in left page
@@ -160,7 +165,7 @@
         splitKey.initData(splitKeySize);
         tupleWriter.writeTupleFields(frameTuple, 0, cmp.getKeyFieldCount(), splitKey.getBuffer(), 0);
         splitKey.getTuple().resetByTupleOffset(splitKey.getBuffer(), 0);
-        
+
         return 0;
     }
 
@@ -181,8 +186,8 @@
         return slotManager.findTupleIndex(searchKey, pageTuple, cmp, ftm, ftp);
     }
 
-	@Override
-	public int getPageHeaderSize() {
-		return nextLeafOff;
-	}
+    @Override
+    public int getPageHeaderSize() {
+        return nextLeafOff;
+    }
 }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrameFactory.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrameFactory.java
index d59b391..a56390b 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrameFactory.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrameFactory.java
@@ -22,7 +22,7 @@
 public class BTreeNSMLeafFrameFactory implements ITreeIndexFrameFactory {
 
     private static final long serialVersionUID = 1L;
-    private ITreeIndexTupleWriterFactory tupleWriterFactory;
+    private final ITreeIndexTupleWriterFactory tupleWriterFactory;
 
     public BTreeNSMLeafFrameFactory(ITreeIndexTupleWriterFactory tupleWriterFactory) {
         this.tupleWriterFactory = tupleWriterFactory;
@@ -32,4 +32,9 @@
     public IBTreeLeafFrame createFrame() {
         return new BTreeNSMLeafFrame(tupleWriterFactory.createTupleWriter());
     }
+
+    @Override
+    public ITreeIndexTupleWriterFactory getTupleWriterFactory() {
+        return tupleWriterFactory;
+    }
 }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTree.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTree.java
index 1869a1b..c1fc5ba 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTree.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTree.java
@@ -51,7 +51,7 @@
     private final static int RESTART_OP = Integer.MIN_VALUE;
     private final static int MAX_RESTARTS = 10;
 
-    // the root page never changes
+    // Fixed root page.
     private final int rootPage = 1;
 
     private final IFreePageManager freePageManager;
@@ -260,23 +260,19 @@
             ctx.pred.setLowKeyComparator(cmp);
         if (ctx.pred.getHighKeyComparator() == null)
             ctx.pred.setHighKeyComparator(cmp);
-
-        boolean repeatOp = true;
         // we use this loop to deal with possibly multiple operation restarts
         // due to ongoing structure modifications during the descent
+        boolean repeatOp = true;
         while (repeatOp && ctx.opRestarts < MAX_RESTARTS) {
             performOp(rootPage, null, ctx);
-
             // if we reach this stage then we need to restart from the (possibly
             // new) root
             if (!ctx.pageLsns.isEmpty() && ctx.pageLsns.getLast() == RESTART_OP) {
                 ctx.pageLsns.removeLast(); // pop the restart op indicator
                 continue;
             }
-
             repeatOp = false;
         }
-
         cursor.setBufferCache(bufferCache);
         cursor.setFileId(fileId);
     }
@@ -308,6 +304,23 @@
         ctx.interiorFrame.setPage(originalPage);
     }
 
+    private void reinitRoot(BTreeOpContext ctx) throws HyracksDataException {
+        ICachedPage rootNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), false);
+        pins++;
+        rootNode.acquireWriteLatch();
+        writeLatchesAcquired++;
+        try {
+            ctx.leafFrame.setPage(rootNode);
+            ctx.leafFrame.initBuffer((byte) 0);
+            currentLevel = 0; // debug
+        } finally {
+            rootNode.releaseWriteLatch();
+            writeLatchesReleased++;
+            bufferCache.unpin(rootNode);
+            unpins++;
+        }
+    }
+    
     private void createNewRoot(BTreeOpContext ctx) throws Exception {
         rootSplits++; // debug
         splitsByLevel[currentLevel]++;
@@ -354,7 +367,7 @@
                     ctx.interiorFrame.setSmFlag(true); // will be cleared later
                     // in unsetSmPages
                     ctx.splitKey.setLeftPage(newLeftId);
-                    int targetTupleIndex = ctx.interiorFrame.findTupleIndex(ctx.splitKey.getTuple(), cmp);
+                    int targetTupleIndex = ctx.interiorFrame.findTupleIndex(ctx.splitKey.getTuple(), cmp, false);
                     ctx.interiorFrame.insert(ctx.splitKey.getTuple(), cmp, targetTupleIndex);
                 } finally {
                     newLeftNode.releaseWriteLatch();
@@ -375,9 +388,8 @@
             unpins++;
         }
     }
-
-    @Override
-    public void insert(ITupleReference tuple, IndexOpContext ictx) throws Exception {
+    
+    private void insertUpdateOrDelete(ITupleReference tuple, IndexOpContext ictx) throws Exception {
         BTreeOpContext ctx = (BTreeOpContext) ictx;
         ctx.reset();
         ctx.pred.setLowKeyComparator(cmp);
@@ -385,171 +397,231 @@
         ctx.pred.setLowKey(tuple, true);
         ctx.pred.setHighKey(tuple, true);
         ctx.splitKey.reset();
-        ctx.splitKey.getTuple().setFieldCount(cmp.getKeyFieldCount());
-
+        ctx.splitKey.getTuple().setFieldCount(cmp.getKeyFieldCount());        
+        // We use this loop to deal with possibly multiple operation restarts
+        // due to ongoing structure modifications during the descent.
         boolean repeatOp = true;
-        // we use this loop to deal with possibly multiple operation restarts
-        // due to ongoing structure modifications during the descent
         while (repeatOp && ctx.opRestarts < MAX_RESTARTS) {
             performOp(rootPage, null, ctx);
-
-            // if we reach this stage then we need to restart from the (possibly
-            // new) root
+            // Do we need to restart from the (possibly new) root?
             if (!ctx.pageLsns.isEmpty() && ctx.pageLsns.getLast() == RESTART_OP) {
                 ctx.pageLsns.removeLast(); // pop the restart op indicator
                 continue;
             }
-
-            // we split the root, here is the key for a new root
+            // Split key propagated?
             if (ctx.splitKey.getBuffer() != null) {
-                createNewRoot(ctx);
+                if (ctx.op == IndexOp.DELETE) {
+                    // Reset level of root to zero.
+                    reinitRoot(ctx);
+                } else {
+                    // Insert or update op. Create a new root.
+                    createNewRoot(ctx);
+                }
             }
-
             unsetSmPages(ctx);
-
+            if (ctx.op == IndexOp.DELETE) {
+                addFreePages(ctx);
+            }
             repeatOp = false;
         }
     }
+    
+    @Override
+    public void insert(ITupleReference tuple, IndexOpContext ictx) throws Exception {
+        insertUpdateOrDelete(tuple, ictx);
+    }
 
+    @Override
+    public void update(ITupleReference tuple, IndexOpContext ictx) throws Exception {
+        insertUpdateOrDelete(tuple, ictx);
+    }
+    
+    @Override
+    public void delete(ITupleReference tuple, IndexOpContext ictx) throws Exception {
+        insertUpdateOrDelete(tuple, ictx);
+    }
+    
     public long uselessCompressionTime = 0;
 
     private void insertLeaf(ICachedPage node, int pageId, ITupleReference tuple, BTreeOpContext ctx) throws Exception {
         ctx.leafFrame.setPage(node);
         ctx.leafFrame.setPageTupleFieldCount(cmp.getFieldCount());
-
-        int targetTupleIndex = ctx.leafFrame.findTupleIndex(tuple, cmp);
+        int targetTupleIndex = ctx.leafFrame.findTupleIndex(tuple, cmp, true);
         FrameOpSpaceStatus spaceStatus = ctx.leafFrame.hasSpaceInsert(tuple, cmp);
         switch (spaceStatus) {
-
             case SUFFICIENT_CONTIGUOUS_SPACE: {
                 // System.out.println("SUFFICIENT_CONTIGUOUS_SPACE");
                 ctx.leafFrame.insert(tuple, cmp, targetTupleIndex);
                 ctx.splitKey.reset();
-            }
                 break;
-
+            }
             case SUFFICIENT_SPACE: {
                 // System.out.println("SUFFICIENT_SPACE");
                 boolean slotsChanged = ctx.leafFrame.compact(cmp);
-                if (slotsChanged)
-                    targetTupleIndex = ctx.leafFrame.findTupleIndex(tuple, cmp);
+                if (slotsChanged) {
+                    targetTupleIndex = ctx.leafFrame.findTupleIndex(tuple, cmp, true);
+                }
                 ctx.leafFrame.insert(tuple, cmp, targetTupleIndex);
                 ctx.splitKey.reset();
-            }
                 break;
-
+            }
             case INSUFFICIENT_SPACE: {
                 // System.out.println("INSUFFICIENT_SPACE");
-
-                // try compressing the page first and see if there is space
-                // available
+                // Try compressing the page first and see if there is space available.
                 long start = System.currentTimeMillis();
                 boolean reCompressed = ctx.leafFrame.compress(cmp);
                 long end = System.currentTimeMillis();
-                if (reCompressed)
+                if (reCompressed) {
                     spaceStatus = ctx.leafFrame.hasSpaceInsert(tuple, cmp);
-
+                }
                 if (spaceStatus == FrameOpSpaceStatus.SUFFICIENT_CONTIGUOUS_SPACE) {
                     ctx.leafFrame.insert(tuple, cmp, targetTupleIndex);
                     ctx.splitKey.reset();
-
                     usefulCompression++;
                 } else {
-
                     uselessCompressionTime += (end - start);
                     uselessCompression++;
+                    performLeafSplit(pageId, tuple, ctx);
+                }
+                break;
+            }
+        }
+        node.releaseWriteLatch();
+        writeLatchesReleased++;
+        bufferCache.unpin(node);
+        unpins++;
+    }
+    
+    private void performLeafSplit(int pageId, ITupleReference tuple, BTreeOpContext ctx) throws Exception {
+        splitsByLevel[0]++; // debug
+        int rightSiblingPageId = ctx.leafFrame.getNextLeaf();
+        ICachedPage rightSibling = null;
+        if (rightSiblingPageId > 0) {
+            rightSibling = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rightSiblingPageId),
+                    false);
+            pins++;
+        }
+        // Lock is released in unsetSmPages(), after sm has fully completed.
+        treeLatch.writeLock().lock(); 
+        treeLatchesAcquired++;
+        try {
 
-                    // perform split
-                    splitsByLevel[0]++; // debug
-                    int rightSiblingPageId = ctx.leafFrame.getNextLeaf();
-                    ICachedPage rightSibling = null;
-                    if (rightSiblingPageId > 0) {
-                        rightSibling = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rightSiblingPageId),
-                                false);
-                        pins++;
-                    }
+            int rightPageId = freePageManager.getFreePage(ctx.metaFrame);
+            ICachedPage rightNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rightPageId),
+                    true);
+            pins++;
+            rightNode.acquireWriteLatch();
+            writeLatchesAcquired++;
+            try {
+                IBTreeLeafFrame rightFrame = (IBTreeLeafFrame) leafFrameFactory.createFrame();
+                rightFrame.setPage(rightNode);
+                rightFrame.initBuffer((byte) 0);
+                rightFrame.setPageTupleFieldCount(cmp.getFieldCount());
 
-                    treeLatch.writeLock().lock(); // lock is released in
-                    // unsetSmPages(), after sm has
-                    // fully completed
-                    treeLatchesAcquired++;
+                int ret = ctx.leafFrame.split(rightFrame, tuple, cmp, ctx.splitKey);
+
+                ctx.smPages.add(pageId);
+                ctx.smPages.add(rightPageId);
+                ctx.leafFrame.setSmFlag(true);
+                rightFrame.setSmFlag(true);
+
+                rightFrame.setNextLeaf(ctx.leafFrame.getNextLeaf());
+                rightFrame.setPrevLeaf(pageId);
+                ctx.leafFrame.setNextLeaf(rightPageId);
+
+                // TODO: we just use increasing numbers as pageLsn,
+                // we
+                // should tie this together with the LogManager and
+                // TransactionManager
+                rightFrame.setPageLsn(rightFrame.getPageLsn() + 1);
+                ctx.leafFrame.setPageLsn(ctx.leafFrame.getPageLsn() + 1);
+
+                if (ret != 0) {
+                    ctx.splitKey.reset();
+                } else {
+                    // System.out.print("LEAF SPLITKEY: ");
+                    // cmp.printKey(splitKey.getData(), 0);
+                    // System.out.println("");
+
+                    ctx.splitKey.setPages(pageId, rightPageId);
+                }
+                if (rightSibling != null) {
+                    rightSibling.acquireWriteLatch();
+                    writeLatchesAcquired++;
                     try {
-
-                        int rightPageId = freePageManager.getFreePage(ctx.metaFrame);
-                        ICachedPage rightNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rightPageId),
-                                true);
-                        pins++;
-                        rightNode.acquireWriteLatch();
-                        writeLatchesAcquired++;
-                        try {
-                            IBTreeLeafFrame rightFrame = (IBTreeLeafFrame) leafFrameFactory.createFrame();
-                            rightFrame.setPage(rightNode);
-                            rightFrame.initBuffer((byte) 0);
-                            rightFrame.setPageTupleFieldCount(cmp.getFieldCount());
-
-                            int ret = ctx.leafFrame.split(rightFrame, tuple, cmp, ctx.splitKey);
-
-                            ctx.smPages.add(pageId);
-                            ctx.smPages.add(rightPageId);
-                            ctx.leafFrame.setSmFlag(true);
-                            rightFrame.setSmFlag(true);
-
-                            rightFrame.setNextLeaf(ctx.leafFrame.getNextLeaf());
-                            rightFrame.setPrevLeaf(pageId);
-                            ctx.leafFrame.setNextLeaf(rightPageId);
-
-                            // TODO: we just use increasing numbers as pageLsn,
-                            // we
-                            // should tie this together with the LogManager and
-                            // TransactionManager
-                            rightFrame.setPageLsn(rightFrame.getPageLsn() + 1);
-                            ctx.leafFrame.setPageLsn(ctx.leafFrame.getPageLsn() + 1);
-
-                            if (ret != 0) {
-                                ctx.splitKey.reset();
-                            } else {
-                                // System.out.print("LEAF SPLITKEY: ");
-                                // cmp.printKey(splitKey.getData(), 0);
-                                // System.out.println("");
-
-                                ctx.splitKey.setPages(pageId, rightPageId);
-                            }
-                            if (rightSibling != null) {
-                                rightSibling.acquireWriteLatch();
-                                writeLatchesAcquired++;
-                                try {
-                                    rightFrame.setPage(rightSibling); // reuse
-                                    // rightFrame
-                                    // for
-                                    // modification
-                                    rightFrame.setPrevLeaf(rightPageId);
-                                } finally {
-                                    rightSibling.releaseWriteLatch();
-                                    writeLatchesReleased++;
-                                }
-                            }
-                        } finally {
-                            rightNode.releaseWriteLatch();
-                            writeLatchesReleased++;
-                            bufferCache.unpin(rightNode);
-                            unpins++;
-                        }
-                    } catch (Exception e) {
-                        treeLatch.writeLock().unlock();
-                        treeLatchesReleased++;
-                        throw e;
+                        rightFrame.setPage(rightSibling); // reuse
+                        // rightFrame
+                        // for
+                        // modification
+                        rightFrame.setPrevLeaf(rightPageId);
                     } finally {
-                        if (rightSibling != null) {
-                            bufferCache.unpin(rightSibling);
-                            unpins++;
-                        }
+                        rightSibling.releaseWriteLatch();
+                        writeLatchesReleased++;
                     }
                 }
+            } finally {
+                rightNode.releaseWriteLatch();
+                writeLatchesReleased++;
+                bufferCache.unpin(rightNode);
+                unpins++;
             }
-                break;
-
+        } catch (Exception e) {
+            treeLatch.writeLock().unlock();
+            treeLatchesReleased++;
+            throw e;
+        } finally {
+            if (rightSibling != null) {
+                bufferCache.unpin(rightSibling);
+                unpins++;
+            }
         }
-
+    }
+    
+    private void updateLeaf(ICachedPage node, int pageId, ITupleReference tuple, BTreeOpContext ctx) throws Exception {
+        ctx.leafFrame.setPage(node);
+        ctx.leafFrame.setPageTupleFieldCount(cmp.getFieldCount());
+        int oldTupleIndex = ctx.leafFrame.findTupleIndex(tuple, cmp, false);
+        FrameOpSpaceStatus spaceStatus = ctx.leafFrame.hasSpaceUpdate(tuple, oldTupleIndex, cmp);
+        switch (spaceStatus) {
+            case SUFFICIENT_INPLACE_SPACE: {
+                //System.out.println("SUFFICIENT_INPLACE_SPACE");
+                ctx.leafFrame.update(tuple, oldTupleIndex, true);
+                ctx.splitKey.reset();
+                break;
+            }
+            case SUFFICIENT_CONTIGUOUS_SPACE: {
+                //System.out.println("SUFFICIENT_CONTIGUOUS_SPACE");
+                ctx.leafFrame.update(tuple, oldTupleIndex, false);
+                ctx.splitKey.reset();
+                break;
+            }                
+            case SUFFICIENT_SPACE: {
+                //System.out.println("SUFFICIENT_SPACE");
+                // Delete the old tuple, compact the frame, and insert the new tuple.
+                ctx.leafFrame.delete(tuple, cmp, false);
+                ctx.leafFrame.compact(cmp);
+                int targetTupleIndex = ctx.leafFrame.findTupleIndex(tuple, cmp, false);
+                ctx.leafFrame.insert(tuple, cmp, targetTupleIndex);
+                ctx.splitKey.reset();
+                break;
+            }                
+            case INSUFFICIENT_SPACE: {
+                //System.out.println("INSUFFICIENT_SPACE");
+                // Delete the old tuple, and try compressing the page to make space available.
+                ctx.leafFrame.delete(tuple, cmp, false);
+                ctx.leafFrame.compress(cmp);
+                // We need to insert the new tuple, so check if there is space.
+                spaceStatus = ctx.leafFrame.hasSpaceInsert(tuple, cmp);                
+                if (spaceStatus == FrameOpSpaceStatus.SUFFICIENT_CONTIGUOUS_SPACE) {
+                    int targetTupleIndex = ctx.leafFrame.findTupleIndex(tuple, cmp, false);
+                    ctx.leafFrame.insert(tuple, cmp, targetTupleIndex);
+                    ctx.splitKey.reset();
+                } else {
+                    performLeafSplit(pageId, tuple, ctx);
+                }
+                break;
+            }
+        }
         node.releaseWriteLatch();
         writeLatchesReleased++;
         bufferCache.unpin(node);
@@ -560,8 +632,7 @@
             throws Exception {
         ctx.interiorFrame.setPage(node);
         ctx.interiorFrame.setPageTupleFieldCount(cmp.getKeyFieldCount());
-
-        int targetTupleIndex = ctx.interiorFrame.findTupleIndex(tuple, cmp);
+        int targetTupleIndex = ctx.interiorFrame.findTupleIndex(tuple, cmp, false);
         FrameOpSpaceStatus spaceStatus = ctx.interiorFrame.hasSpaceInsert(tuple, cmp);
         switch (spaceStatus) {
             case INSUFFICIENT_SPACE: {
@@ -618,8 +689,9 @@
 
             case SUFFICIENT_SPACE: {
                 boolean slotsChanged = ctx.interiorFrame.compact(cmp);
+                // TODO: do we really need to check for duplicates here?
                 if (slotsChanged)
-                    targetTupleIndex = ctx.interiorFrame.findTupleIndex(tuple, cmp);
+                    targetTupleIndex = ctx.interiorFrame.findTupleIndex(tuple, cmp, true);
                 ctx.interiorFrame.insert(tuple, cmp, targetTupleIndex);
                 ctx.splitKey.reset();
             }
@@ -628,56 +700,6 @@
         }
     }
 
-    @Override
-    public void delete(ITupleReference tuple, IndexOpContext ictx) throws Exception {
-        BTreeOpContext ctx = (BTreeOpContext) ictx;
-        ctx.reset();
-        ctx.pred.setLowKeyComparator(cmp);
-        ctx.pred.setHighKeyComparator(cmp);
-        ctx.pred.setLowKey(tuple, true);
-        ctx.pred.setHighKey(tuple, true);
-        ctx.splitKey.reset();
-        ctx.splitKey.getTuple().setFieldCount(cmp.getKeyFieldCount());
-
-        boolean repeatOp = true;
-        // we use this loop to deal with possibly multiple operation restarts
-        // due to ongoing structure modifications during the descent
-        while (repeatOp && ctx.opRestarts < MAX_RESTARTS) {
-            performOp(rootPage, null, ctx);
-
-            // if we reach this stage then we need to restart from the (possibly
-            // new) root
-            if (!ctx.pageLsns.isEmpty() && ctx.pageLsns.getLast() == RESTART_OP) {
-                ctx.pageLsns.removeLast(); // pop the restart op indicator
-                continue;
-            }
-
-            // tree is empty, reset level to zero
-            if (ctx.splitKey.getBuffer() != null) {
-                ICachedPage rootNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), false);
-                pins++;
-                rootNode.acquireWriteLatch();
-                writeLatchesAcquired++;
-                try {
-                    ctx.leafFrame.setPage(rootNode);
-                    ctx.leafFrame.initBuffer((byte) 0);
-                    currentLevel = 0; // debug
-                } finally {
-                    rootNode.releaseWriteLatch();
-                    writeLatchesReleased++;
-                    bufferCache.unpin(rootNode);
-                    unpins++;
-                }
-            }
-
-            unsetSmPages(ctx);
-
-            addFreePages(ctx);
-
-            repeatOp = false;
-        }
-    }
-
     // TODO: to avoid latch deadlock, must modify cursor to detect empty leaves
     private void deleteLeaf(ICachedPage node, int pageId, ITupleReference tuple, BTreeOpContext ctx) throws Exception {
         ctx.leafFrame.setPage(node);
@@ -817,7 +839,7 @@
     }
 
     private final void acquireLatch(ICachedPage node, IndexOp op, boolean isLeaf) {
-        if (isLeaf && (op.equals(IndexOp.INSERT) || op.equals(IndexOp.DELETE))) {
+        if (isLeaf && (op.equals(IndexOp.INSERT) || op.equals(IndexOp.DELETE) || op.equals(IndexOp.UPDATE))) {
             node.acquireWriteLatch();
             writeLatchesAcquired++;
         } else {
@@ -827,7 +849,7 @@
     }
 
     private final void releaseLatch(ICachedPage node, IndexOp op, boolean isLeaf) {
-        if (isLeaf && (op.equals(IndexOp.INSERT) || op.equals(IndexOp.DELETE))) {
+        if (isLeaf && (op.equals(IndexOp.INSERT) || op.equals(IndexOp.DELETE) || op.equals(IndexOp.UPDATE))) {
             node.releaseWriteLatch();
             writeLatchesReleased++;
         } else {
@@ -870,7 +892,6 @@
         // remember trail of pageLsns, to unwind recursion in case of an ongoing
         // structure modification
         ctx.pageLsns.add(ctx.interiorFrame.getPageLsn());
-
         try {
 
             // latch coupling, note: parent should never be write latched,
@@ -884,68 +905,48 @@
 
             if (!isLeaf || smFlag) {
                 if (!smFlag) {
-                    // we use this loop to deal with possibly multiple operation
+                    // We use this loop to deal with possibly multiple operation
                     // restarts due to ongoing structure modifications during
-                    // the descent
+                    // the descent.
                     boolean repeatOp = true;
                     while (repeatOp && ctx.opRestarts < MAX_RESTARTS) {
                         int childPageId = ctx.interiorFrame.getChildPageId(ctx.pred, cmp);
                         performOp(childPageId, node, ctx);
 
                         if (!ctx.pageLsns.isEmpty() && ctx.pageLsns.getLast() == RESTART_OP) {
-                            ctx.pageLsns.removeLast(); // pop the restart op
-                            // indicator
+                            // Pop the restart op indicator.
+                            ctx.pageLsns.removeLast();
                             if (isConsistent(pageId, ctx)) {
-                                node = null; // to avoid unpinning and
-                                // unlatching node again in
-                                // recursive call
-                                continue; // descend the tree again
+                                // Don't unpin and unlatch node again in recursive call.
+                                node = null; 
+                                // Descend the tree again.
+                                continue;
                             } else {
-                                ctx.pageLsns.removeLast(); // pop pageLsn of
-                                // this page
-                                // (version seen by this op
-                                // during descent)
-                                ctx.pageLsns.add(RESTART_OP); // this node is
-                                // not
-                                // consistent,
-                                // set the
-                                // restart
-                                // indicator for
-                                // upper level
+                                // Pop pageLsn of this page (version seen by this op during descent).
+                                ctx.pageLsns.removeLast(); 
+                                // This node is not consistent set the restart indicator for upper level.
+                                ctx.pageLsns.add(RESTART_OP);
                                 break;
                             }
                         }
-
+                        
                         switch (ctx.op) {
-
-                            case INSERT: {
-                                if (ctx.splitKey.getBuffer() != null) {
-                                    node = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, pageId), false);
-                                    pins++;
-                                    node.acquireWriteLatch();
-                                    writeLatchesAcquired++;
-                                    try {
-                                        insertInterior(node, pageId, ctx.splitKey.getTuple(), ctx);
-                                    } finally {
-                                        node.releaseWriteLatch();
-                                        writeLatchesReleased++;
-                                        bufferCache.unpin(node);
-                                        unpins++;
-                                    }
-                                } else {
-                                    unsetSmPages(ctx);
-                                }
-                            }
-                                break;
-
+                            case INSERT:
+                            case UPDATE:
                             case DELETE: {
+                                // Is there a propagated split key?
                                 if (ctx.splitKey.getBuffer() != null) {
                                     node = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, pageId), false);
                                     pins++;
                                     node.acquireWriteLatch();
                                     writeLatchesAcquired++;
                                     try {
-                                        deleteInterior(node, pageId, ctx.pred.getLowKey(), ctx);
+                                        if (ctx.op == IndexOp.DELETE) {
+                                            deleteInterior(node, pageId, ctx.pred.getLowKey(), ctx);                                            
+                                        } else {
+                                            // Insert or update op. Both can cause split keys to propagate upwards.
+                                            insertInterior(node, pageId, ctx.splitKey.getTuple(), ctx);
+                                        }
                                     } finally {
                                         node.releaseWriteLatch();
                                         writeLatchesReleased++;
@@ -955,18 +956,15 @@
                                 } else {
                                     unsetSmPages(ctx);
                                 }
-                            }
                                 break;
-
-                            case SEARCH: {
-                                // do nothing
                             }
+                            default: {
+                                // Do nothing for SEARCH and DISKORDERSCAN.
                                 break;
-
+                            }
                         }
-
-                        repeatOp = false; // operation completed
-
+                        // Operation completed.
+                        repeatOp = false;
                     } // end while
                 } else { // smFlag
                     ctx.opRestarts++;
@@ -995,19 +993,21 @@
                 switch (ctx.op) {
                     case INSERT: {
                         insertLeaf(node, pageId, ctx.pred.getLowKey(), ctx);
-                    }
                         break;
-
+                    }
+                    case UPDATE: {
+                        updateLeaf(node, pageId, ctx.pred.getLowKey(), ctx);
+                        break;
+                    }
                     case DELETE: {
                         deleteLeaf(node, pageId, ctx.pred.getLowKey(), ctx);
-                    }
                         break;
-
+                    }
                     case SEARCH: {
                         ctx.cursorInitialState.setPage(node);
                         ctx.cursor.open(ctx.cursorInitialState, ctx.pred);
-                    }
                         break;
+                    }
                 }
             }
         } catch (TreeIndexException e) {
@@ -1271,12 +1271,7 @@
 
     public int getRootPageId() {
         return rootPage;
-    }
-
-    @Override
-    public void update(ITupleReference tuple, IndexOpContext ictx) throws Exception {
-        throw new Exception("BTree Update not implemented.");
-    }
+    }    
 
     @Override
     public int getFieldCount() {
@@ -1287,4 +1282,4 @@
     public IndexType getIndexType() {
         return IndexType.BTREE;
     }
-}
\ No newline at end of file
+}
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeDuplicateKeyException.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeDuplicateKeyException.java
new file mode 100644
index 0000000..1aa7fff
--- /dev/null
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeDuplicateKeyException.java
@@ -0,0 +1,13 @@
+package edu.uci.ics.hyracks.storage.am.btree.impls;
+
+public class BTreeDuplicateKeyException extends BTreeException {
+    private static final long serialVersionUID = 1L;
+    
+    public BTreeDuplicateKeyException(Exception e) {
+        super(e);
+    }
+    
+    public BTreeDuplicateKeyException(String message) {
+        super(message);
+    }
+}
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeException.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeException.java
index 8019bcb..1658989 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeException.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeException.java
@@ -19,8 +19,8 @@
 
 public class BTreeException extends TreeIndexException {
 
-    private static final long serialVersionUID = 1L;
-    private boolean handled = false;
+    protected static final long serialVersionUID = 1L;
+    protected boolean handled = false;
 
     public BTreeException(Exception e) {
         super(e);
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java
index 6d65b14..bacd16c 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java
@@ -43,18 +43,18 @@
         this.leafFrame = leafFrame;
         this.interiorFrame = interiorFrame;
         this.metaFrame = metaFrame;
-
         pageLsns = new IntArrayList(treeHeightHint, treeHeightHint);
-        if (op != IndexOp.SEARCH && op != IndexOp.DISKORDERSCAN) {
+        if (op == IndexOp.SEARCH || op == IndexOp.DISKORDERSCAN) {
+            smPages = null;
+            freePages = null;
+            splitKey = null;
+            cursorInitialState = new BTreeCursorInitialState(null);            
+        } else {
+            // Insert, update or delete operation.
             smPages = new IntArrayList(treeHeightHint, treeHeightHint);
             freePages = new IntArrayList(treeHeightHint, treeHeightHint);
             pred = new RangePredicate(true, null, null, true, true, null, null);
             splitKey = new BTreeSplitKey(leafFrame.getTupleWriter().createTupleReference());
-        } else {
-            smPages = null;
-            freePages = null;
-            splitKey = null;
-            cursorInitialState = new BTreeCursorInitialState(null);
         }
     }
 
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/FieldPrefixTupleReference.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/FieldPrefixTupleReference.java
index 9a655fc..a025d57 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/FieldPrefixTupleReference.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/FieldPrefixTupleReference.java
@@ -90,4 +90,10 @@
     public void resetByTupleOffset(ByteBuffer buf, int tupleStartOffset) {
         frame = null;
     }
+
+    @Override
+    public int getTupleSize() {
+        // TODO Auto-generated method stub
+        return 0;
+    }
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexFrame.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexFrame.java
index db458ec..55ec352 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexFrame.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexFrame.java
@@ -25,86 +25,80 @@
 import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
 
 public interface ITreeIndexFrame {
-	public void setPage(ICachedPage page);
+    public void setPage(ICachedPage page);
 
-	public ICachedPage getPage();
+    public ICachedPage getPage();
 
-	public ByteBuffer getBuffer();
+    public ByteBuffer getBuffer();
 
-	public int findTupleIndex(ITupleReference tuple, MultiComparator cmp)
-			throws Exception;
+    public int findTupleIndex(ITupleReference tuple, MultiComparator cmp, boolean throwIfKeyExists) throws Exception;
 
-	public void insert(ITupleReference tuple, MultiComparator cmp,
-			int tupleIndex) throws Exception;
+    public void insert(ITupleReference tuple, MultiComparator cmp, int tupleIndex) throws Exception;
 
-	public void update(int rid, ITupleReference tuple) throws Exception;
+    public void update(ITupleReference newTuple, int oldTupleIndex, boolean inPlace) throws Exception;
 
-	public void delete(ITupleReference tuple, MultiComparator cmp,
-			boolean exactDelete) throws Exception;
+    public void delete(ITupleReference tuple, MultiComparator cmp, boolean exactDelete) throws Exception;
 
-	// returns true if slots were modified, false otherwise
-	public boolean compact(MultiComparator cmp);
+    // returns true if slots were modified, false otherwise
+    public boolean compact(MultiComparator cmp);
 
-	public boolean compress(MultiComparator cmp) throws HyracksDataException;
+    public boolean compress(MultiComparator cmp) throws HyracksDataException;
 
-	public void initBuffer(byte level);
+    public void initBuffer(byte level);
 
-	public int getTupleCount();
+    public int getTupleCount();
 
-	// assumption: page must be write-latched at this point
-	public FrameOpSpaceStatus hasSpaceInsert(ITupleReference tuple,
-			MultiComparator cmp);
+    // assumption: page must be write-latched at this point
+    public FrameOpSpaceStatus hasSpaceInsert(ITupleReference tuple, MultiComparator cmp);
 
-	public FrameOpSpaceStatus hasSpaceUpdate(int rid, ITupleReference tuple,
-			MultiComparator cmp);
+    public FrameOpSpaceStatus hasSpaceUpdate(ITupleReference newTuple, int oldTupleIndex, MultiComparator cmp);
 
-	public int getTupleOffset(int slotNum);
+    public int getTupleOffset(int slotNum);
 
-	public int getTotalFreeSpace();
+    public int getTotalFreeSpace();
 
-	public void setPageLsn(int pageLsn);
+    public void setPageLsn(int pageLsn);
 
-	public int getPageLsn();
+    public int getPageLsn();
 
-	// for debugging
-	public void printHeader();
+    // for debugging
+    public void printHeader();
 
-	public String printKeys(MultiComparator cmp,
-			ISerializerDeserializer[] fields) throws HyracksDataException;
+    public String printKeys(MultiComparator cmp, ISerializerDeserializer[] fields) throws HyracksDataException;
 
-	// TODO; what if tuples more than half-page size?
-	public int split(ITreeIndexFrame rightFrame, ITupleReference tuple,
-			MultiComparator cmp, ISplitKey splitKey) throws Exception;
+    // TODO; what if tuples more than half-page size?
+    public int split(ITreeIndexFrame rightFrame, ITupleReference tuple, MultiComparator cmp, ISplitKey splitKey)
+            throws Exception;
 
-	public ISlotManager getSlotManager();
+    public ISlotManager getSlotManager();
 
-	// ATTENTION: in b-tree operations it may not always be possible to
-	// determine whether an ICachedPage is a leaf or interior node
-	// a compatible interior and leaf implementation MUST return identical
-	// values when given the same ByteBuffer for the functions below
-	public boolean isLeaf();
+    // ATTENTION: in b-tree operations it may not always be possible to
+    // determine whether an ICachedPage is a leaf or interior node
+    // a compatible interior and leaf implementation MUST return identical
+    // values when given the same ByteBuffer for the functions below
+    public boolean isLeaf();
 
-	public boolean isInterior();
+    public boolean isInterior();
 
-	public byte getLevel();
+    public byte getLevel();
 
-	public void setLevel(byte level);
+    public void setLevel(byte level);
 
-	public boolean getSmFlag(); // structure modification flag
+    public boolean getSmFlag(); // structure modification flag
 
-	public void setSmFlag(boolean smFlag);
+    public void setSmFlag(boolean smFlag);
 
-	public int getSlotSize();
+    public int getSlotSize();
 
-	// TODO: should be removed after new tuple format
-	public void setPageTupleFieldCount(int fieldCount);
+    // TODO: should be removed after new tuple format
+    public void setPageTupleFieldCount(int fieldCount);
 
-	// for debugging
-	public int getFreeSpaceOff();
+    // for debugging
+    public int getFreeSpaceOff();
 
-	public void setFreeSpaceOff(int freeSpace);
+    public void setFreeSpaceOff(int freeSpace);
 
-	public ITreeIndexTupleWriter getTupleWriter();
+    public ITreeIndexTupleWriter getTupleWriter();
 
-	public int getPageHeaderSize();
+    public int getPageHeaderSize();
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexFrameFactory.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexFrameFactory.java
index 9ec69d9..32c77be 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexFrameFactory.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexFrameFactory.java
@@ -3,5 +3,6 @@
 import java.io.Serializable;
 
 public interface ITreeIndexFrameFactory extends Serializable {
-	public ITreeIndexFrame createFrame();
+    public ITreeIndexFrame createFrame();
+    public ITreeIndexTupleWriterFactory getTupleWriterFactory();
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexTupleReference.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexTupleReference.java
index 8b845ac..b989dd9 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexTupleReference.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexTupleReference.java
@@ -20,11 +20,13 @@
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 
 public interface ITreeIndexTupleReference extends ITupleReference {
-	public void setFieldCount(int fieldCount);
+    public void setFieldCount(int fieldCount);
 
-	public void setFieldCount(int fieldStartIndex, int fieldCount);
+    public void setFieldCount(int fieldStartIndex, int fieldCount);
 
-	public void resetByTupleOffset(ByteBuffer buf, int tupleStartOffset);
+    public void resetByTupleOffset(ByteBuffer buf, int tupleStartOffset);
 
-	public void resetByTupleIndex(ITreeIndexFrame frame, int tupleIndex);
+    public void resetByTupleIndex(ITreeIndexFrame frame, int tupleIndex);
+    
+    public int getTupleSize();
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexTupleWriter.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexTupleWriter.java
index 6cd12fb..f0bb7aa 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexTupleWriter.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/ITreeIndexTupleWriter.java
@@ -20,20 +20,21 @@
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 
 public interface ITreeIndexTupleWriter {
-	public int writeTuple(ITupleReference tuple, ByteBuffer targetBuf,
-			int targetOff);
+    public int writeTuple(ITupleReference tuple, ByteBuffer targetBuf, int targetOff);
+    
+    public int writeTuple(ITupleReference tuple, byte[] targetBuf, int targetOff);
 
-	public int bytesRequired(ITupleReference tuple);
+    public int bytesRequired(ITupleReference tuple);
 
-	public int writeTupleFields(ITupleReference tuple, int startField,
-			int numFields, ByteBuffer targetBuf, int targetOff);
+    // TODO: change to byte[] as well.
+    public int writeTupleFields(ITupleReference tuple, int startField, int numFields, ByteBuffer targetBuf,
+            int targetOff);
 
-	public int bytesRequired(ITupleReference tuple, int startField,
-			int numFields);
+    public int bytesRequired(ITupleReference tuple, int startField, int numFields);
 
-	// return a tuplereference instance that can read the tuple written by this
-	// writer
-	// the main idea is that the format of the written tuple may not be the same
-	// as the format written by this writer
-	public ITreeIndexTupleReference createTupleReference();
+    // return a tuplereference instance that can read the tuple written by this
+    // writer
+    // the main idea is that the format of the written tuple may not be the same
+    // as the format written by this writer
+    public ITreeIndexTupleReference createTupleReference();
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexOpHelper.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexOpHelper.java
index f9fd77d..2064753 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexOpHelper.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexOpHelper.java
@@ -30,170 +30,131 @@
 
 public abstract class TreeIndexOpHelper {
 
-	protected ITreeIndexFrame interiorFrame;
-	protected ITreeIndexFrame leafFrame;
-	protected MultiComparator cmp;
+    protected ITreeIndexFrame interiorFrame;
+    protected ITreeIndexFrame leafFrame;
+    protected MultiComparator cmp;
 
-	protected ITreeIndex treeIndex;
-	protected int indexFileId = -1;
-	protected int partition;
+    protected ITreeIndex treeIndex;
+    protected int indexFileId = -1;
+    protected int partition;
 
-	protected ITreeIndexOperatorDescriptorHelper opDesc;
-	protected IHyracksTaskContext ctx;
+    protected ITreeIndexOperatorDescriptorHelper opDesc;
+    protected IHyracksTaskContext ctx;
 
-	protected IndexHelperOpenMode mode;
+    protected IndexHelperOpenMode mode;
 
-	public TreeIndexOpHelper(ITreeIndexOperatorDescriptorHelper opDesc,
-			final IHyracksTaskContext ctx, int partition,
-			IndexHelperOpenMode mode) {
-		this.opDesc = opDesc;
-		this.ctx = ctx;
-		this.mode = mode;
-		this.partition = partition;
-	}
+    public TreeIndexOpHelper(ITreeIndexOperatorDescriptorHelper opDesc, final IHyracksTaskContext ctx,
+            int partition, IndexHelperOpenMode mode) {
+        this.opDesc = opDesc;
+        this.ctx = ctx;
+        this.mode = mode;
+        this.partition = partition;
+    }
 
-	public void init() throws HyracksDataException {
-		IBufferCache bufferCache = opDesc.getStorageManager().getBufferCache(
-				ctx);
-		IFileMapProvider fileMapProvider = opDesc.getStorageManager()
-				.getFileMapProvider(ctx);
-		IFileSplitProvider fileSplitProvider = opDesc
-				.getTreeIndexFileSplitProvider();
+    public void init() throws HyracksDataException {
+        IBufferCache bufferCache = opDesc.getStorageManager().getBufferCache(ctx);
+        IFileMapProvider fileMapProvider = opDesc.getStorageManager().getFileMapProvider(ctx);
+        IFileSplitProvider fileSplitProvider = opDesc.getTreeIndexFileSplitProvider();
 
-		FileReference f = fileSplitProvider.getFileSplits()[partition]
-				.getLocalFile();
-		boolean fileIsMapped = fileMapProvider.isMapped(f);
+        FileReference f = fileSplitProvider.getFileSplits()[partition].getLocalFile();
+        boolean fileIsMapped = fileMapProvider.isMapped(f);
+        if (!fileIsMapped) {
+        	bufferCache.createFile(f);
+        }
+        int fileId = fileMapProvider.lookupFileId(f);
+        try {
+            bufferCache.openFile(fileId);
+        } catch (HyracksDataException e) {
+            // Revert state of buffer cache since file failed to open.
+            if (!fileIsMapped) {
+                bufferCache.deleteFile(fileId);
+            }
+            throw e;
+        }
 
-		switch (mode) {
+        // Only set indexFileId member when openFile() succeeds,
+        // otherwise deinit() will try to close the file that failed to open
+        indexFileId = fileId;
 
-		case OPEN: {
-			if (!fileIsMapped) {
-				throw new HyracksDataException(
-						"Trying to open tree index from unmapped file "
-								+ f.toString());
-			}
-		}
-			break;
+        interiorFrame = opDesc.getTreeIndexInteriorFactory().createFrame();
+        leafFrame = opDesc.getTreeIndexLeafFactory().createFrame();
 
-		case CREATE:
-		case ENLIST: {
-			if (!fileIsMapped) {
-				bufferCache.createFile(f);
-			}
-		}
-			break;
+        IndexRegistry<ITreeIndex> treeIndexRegistry = opDesc.getTreeIndexRegistryProvider().getRegistry(ctx);
+        treeIndex = treeIndexRegistry.get(indexFileId);
+        if (treeIndex == null) {
+            // Create new tree and register it.
+            treeIndexRegistry.lock();
+            try {
+                // Check if tree has already been registered by another thread.
+                treeIndex = treeIndexRegistry.get(indexFileId);
+                if (treeIndex == null) {
+                    // This thread should create and register the tree.
+                    IBinaryComparator[] comparators = new IBinaryComparator[opDesc.getTreeIndexComparatorFactories().length];
+                    for (int i = 0; i < opDesc.getTreeIndexComparatorFactories().length; i++) {
+                        comparators[i] = opDesc.getTreeIndexComparatorFactories()[i].createBinaryComparator();
+                    }
+                    cmp = createMultiComparator(comparators);
+                    treeIndex = createTreeIndex();
+                    if (mode == IndexHelperOpenMode.CREATE) {
+                        ITreeIndexMetaDataFrame metaFrame = treeIndex.getFreePageManager().getMetaDataFrameFactory()
+                                .createFrame();
+                        try {
+                            treeIndex.create(indexFileId, leafFrame, metaFrame);
+                        } catch (Exception e) {
+                            throw new HyracksDataException(e);
+                        }
+                    }
+                    treeIndex.open(indexFileId);
+                    treeIndexRegistry.register(indexFileId, treeIndex);
+                }
+            } finally {
+                treeIndexRegistry.unlock();
+            }
+        }
+    }
 
-		}
+    // MUST be overridden
+    public ITreeIndex createTreeIndex() throws HyracksDataException {
+        throw new HyracksDataException("createTreeIndex Operation not implemented.");
+    }
 
-		int fileId = fileMapProvider.lookupFileId(f);
-		try {
-			bufferCache.openFile(fileId);
-		} catch (HyracksDataException e) {
-			// revert state of buffer cache since file failed to open
-			if (!fileIsMapped) {
-				bufferCache.deleteFile(fileId);
-			}
-			throw e;
-		}
+    // MUST be overridden
+    public MultiComparator createMultiComparator(IBinaryComparator[] comparators) throws HyracksDataException {
+        throw new HyracksDataException("createComparator Operation not implemented.");
+    }
 
-		// only set indexFileId member when openFile() succeeds,
-		// otherwise deinit() will try to close the file that failed to open
-		indexFileId = fileId;
+    public ITreeIndexCursor createDiskOrderScanCursor(ITreeIndexFrame leafFrame) throws HyracksDataException {
+        return new TreeDiskOrderScanCursor(leafFrame);
+    }
 
-		interiorFrame = opDesc.getTreeIndexInteriorFactory().createFrame();
-		leafFrame = opDesc.getTreeIndexLeafFactory().createFrame();
+    public void deinit() throws HyracksDataException {
+        if (indexFileId != -1) {
+            IBufferCache bufferCache = opDesc.getStorageManager().getBufferCache(ctx);
+            bufferCache.closeFile(indexFileId);
+        }
+    }
 
-		IndexRegistry<ITreeIndex> treeIndexRegistry = opDesc
-				.getTreeIndexRegistryProvider().getRegistry(ctx);
-		treeIndex = treeIndexRegistry.get(indexFileId);
-		if (treeIndex == null) {
+    public ITreeIndex getTreeIndex() {
+        return treeIndex;
+    }
 
-			// create new tree and register it
-			treeIndexRegistry.lock();
-			try {
-				// check if tree has already been registered by another thread
-				treeIndex = treeIndexRegistry.get(indexFileId);
-				if (treeIndex == null) {
-					// this thread should create and register the tree
+    public IHyracksTaskContext getHyracksTaskContext() {
+        return ctx;
+    }
 
-					IBinaryComparator[] comparators = new IBinaryComparator[opDesc
-							.getTreeIndexComparatorFactories().length];
-					for (int i = 0; i < opDesc
-							.getTreeIndexComparatorFactories().length; i++) {
-						comparators[i] = opDesc
-								.getTreeIndexComparatorFactories()[i]
-								.createBinaryComparator();
-					}
+    public ITreeIndexOperatorDescriptorHelper getOperatorDescriptor() {
+        return opDesc;
+    }
 
-					cmp = createMultiComparator(comparators);
+    public ITreeIndexFrame getLeafFrame() {
+        return leafFrame;
+    }
 
-					treeIndex = createTreeIndex();
-					if (mode == IndexHelperOpenMode.CREATE) {
-						ITreeIndexMetaDataFrame metaFrame = treeIndex
-								.getFreePageManager().getMetaDataFrameFactory()
-								.createFrame();
-						try {
-							treeIndex.create(indexFileId, leafFrame, metaFrame);
-						} catch (Exception e) {
-							throw new HyracksDataException(e);
-						}
-					}
-					treeIndex.open(indexFileId);
-					treeIndexRegistry.register(indexFileId, treeIndex);
-				}
-			} finally {
-				treeIndexRegistry.unlock();
-			}
-		}
-	}
+    public ITreeIndexFrame getInteriorFrame() {
+        return interiorFrame;
+    }
 
-	// MUST be overridden
-	public ITreeIndex createTreeIndex() throws HyracksDataException {
-		throw new HyracksDataException(
-				"createTreeIndex Operation not implemented.");
-	}
-
-	// MUST be overridden
-	public MultiComparator createMultiComparator(IBinaryComparator[] comparators)
-			throws HyracksDataException {
-		throw new HyracksDataException(
-				"createComparator Operation not implemented.");
-	}
-
-	public ITreeIndexCursor createDiskOrderScanCursor(ITreeIndexFrame leafFrame)
-			throws HyracksDataException {
-		return new TreeDiskOrderScanCursor(leafFrame);
-	}
-
-	public void deinit() throws HyracksDataException {
-		if (indexFileId != -1) {
-			IBufferCache bufferCache = opDesc.getStorageManager()
-					.getBufferCache(ctx);
-			bufferCache.closeFile(indexFileId);
-		}
-	}
-
-	public ITreeIndex getTreeIndex() {
-		return treeIndex;
-	}
-
-	public IHyracksTaskContext getHyracksTaskContext() {
-		return ctx;
-	}
-
-	public ITreeIndexOperatorDescriptorHelper getOperatorDescriptor() {
-		return opDesc;
-	}
-
-	public ITreeIndexFrame getLeafFrame() {
-		return leafFrame;
-	}
-
-	public ITreeIndexFrame getInteriorFrame() {
-		return interiorFrame;
-	}
-
-	public int getIndexFileId() {
-		return indexFileId;
-	}
+    public int getIndexFileId() {
+        return indexFileId;
+    }
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/frames/FrameOpSpaceStatus.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/frames/FrameOpSpaceStatus.java
index 7114875..da9c815 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/frames/FrameOpSpaceStatus.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/frames/FrameOpSpaceStatus.java
@@ -16,5 +16,5 @@
 package edu.uci.ics.hyracks.storage.am.common.frames;
 
 public enum FrameOpSpaceStatus {
-	INSUFFICIENT_SPACE, SUFFICIENT_CONTIGUOUS_SPACE, SUFFICIENT_SPACE
+    INSUFFICIENT_SPACE, SUFFICIENT_CONTIGUOUS_SPACE, SUFFICIENT_SPACE, SUFFICIENT_INPLACE_SPACE
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/frames/TreeIndexNSMFrame.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/frames/TreeIndexNSMFrame.java
index e5c37ff..82309a4 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/frames/TreeIndexNSMFrame.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/frames/TreeIndexNSMFrame.java
@@ -38,309 +38,322 @@
 
 public abstract class TreeIndexNSMFrame implements ITreeIndexFrame {
 
-	protected static final int pageLsnOff = 0; // 0
-	protected static final int tupleCountOff = pageLsnOff + 4; // 4
-	protected static final int freeSpaceOff = tupleCountOff + 4; // 8
-	protected static final int totalFreeSpaceOff = freeSpaceOff + 4; // 16
-	protected static final byte levelOff = totalFreeSpaceOff + 4;
-	protected static final byte smFlagOff = levelOff + 1;
+    protected static final int pageLsnOff = 0; // 0
+    protected static final int tupleCountOff = pageLsnOff + 4; // 4
+    protected static final int freeSpaceOff = tupleCountOff + 4; // 8
+    protected static final int totalFreeSpaceOff = freeSpaceOff + 4; // 16
+    protected static final byte levelOff = totalFreeSpaceOff + 4;
+    protected static final byte smFlagOff = levelOff + 1;
 
-	protected ICachedPage page = null;
-	protected ByteBuffer buf = null;
-	protected ISlotManager slotManager;
+    protected ICachedPage page = null;
+    protected ByteBuffer buf = null;
+    protected ISlotManager slotManager;
 
-	protected ITreeIndexTupleWriter tupleWriter;
-	protected ITreeIndexTupleReference frameTuple;
+    protected ITreeIndexTupleWriter tupleWriter;
+    protected ITreeIndexTupleReference frameTuple;
 
-	public TreeIndexNSMFrame(ITreeIndexTupleWriter tupleWriter,
-			ISlotManager slotManager) {
-		this.tupleWriter = tupleWriter;
-		this.frameTuple = tupleWriter.createTupleReference();
-		this.slotManager = slotManager;
-	}
+    public TreeIndexNSMFrame(ITreeIndexTupleWriter tupleWriter, ISlotManager slotManager) {
+        this.tupleWriter = tupleWriter;
+        this.frameTuple = tupleWriter.createTupleReference();
+        this.slotManager = slotManager;
+    }
 
-	@Override
-	public void initBuffer(byte level) {
-		buf.putInt(pageLsnOff, 0); // TODO: might to set to a different lsn
-		// during creation
-		buf.putInt(tupleCountOff, 0);
-		resetSpaceParams();
-		buf.put(levelOff, level);
-		buf.put(smFlagOff, (byte) 0);
-	}
+    @Override
+    public void initBuffer(byte level) {
+        buf.putInt(pageLsnOff, 0); // TODO: might to set to a different lsn
+        // during creation
+        buf.putInt(tupleCountOff, 0);
+        resetSpaceParams();
+        buf.put(levelOff, level);
+        buf.put(smFlagOff, (byte) 0);
+    }
 
-	@Override
-	public boolean isLeaf() {
-		return buf.get(levelOff) == 0;
-	}
+    @Override
+    public boolean isLeaf() {
+        return buf.get(levelOff) == 0;
+    }
 
-	@Override
-	public boolean isInterior() {
-		return buf.get(levelOff) > 0;
-	}
+    @Override
+    public boolean isInterior() {
+        return buf.get(levelOff) > 0;
+    }
 
-	@Override
-	public byte getLevel() {
-		return buf.get(levelOff);
-	}
+    @Override
+    public byte getLevel() {
+        return buf.get(levelOff);
+    }
 
-	@Override
-	public void setLevel(byte level) {
-		buf.put(levelOff, level);
-	}
+    @Override
+    public void setLevel(byte level) {
+        buf.put(levelOff, level);
+    }
 
-	@Override
-	public boolean getSmFlag() {
-		return buf.get(smFlagOff) != 0;
-	}
+    @Override
+    public boolean getSmFlag() {
+        return buf.get(smFlagOff) != 0;
+    }
 
-	@Override
-	public void setSmFlag(boolean smFlag) {
-		if (smFlag)
-			buf.put(smFlagOff, (byte) 1);
-		else
-			buf.put(smFlagOff, (byte) 0);
-	}
+    @Override
+    public void setSmFlag(boolean smFlag) {
+        if (smFlag)
+            buf.put(smFlagOff, (byte) 1);
+        else
+            buf.put(smFlagOff, (byte) 0);
+    }
 
-	@Override
-	public int getFreeSpaceOff() {
-		return buf.getInt(freeSpaceOff);
-	}
+    @Override
+    public int getFreeSpaceOff() {
+        return buf.getInt(freeSpaceOff);
+    }
 
-	@Override
-	public void setFreeSpaceOff(int freeSpace) {
-		buf.putInt(freeSpaceOff, freeSpace);
-	}
+    @Override
+    public void setFreeSpaceOff(int freeSpace) {
+        buf.putInt(freeSpaceOff, freeSpace);
+    }
 
-	@Override
-	public void setPage(ICachedPage page) {
-		this.page = page;
-		this.buf = page.getBuffer();
-		slotManager.setFrame(this);
-	}
+    @Override
+    public void setPage(ICachedPage page) {
+        this.page = page;
+        this.buf = page.getBuffer();
+        slotManager.setFrame(this);
+    }
 
-	@Override
-	public ByteBuffer getBuffer() {
-		return page.getBuffer();
-	}
+    @Override
+    public ByteBuffer getBuffer() {
+        return page.getBuffer();
+    }
 
-	@Override
-	public ICachedPage getPage() {
-		return page;
-	}
+    @Override
+    public ICachedPage getPage() {
+        return page;
+    }
 
-	@Override
-	public boolean compact(MultiComparator cmp) {
-		resetSpaceParams();
-		frameTuple.setFieldCount(cmp.getFieldCount());
+    @Override
+    public boolean compact(MultiComparator cmp) {
+        resetSpaceParams();
+        frameTuple.setFieldCount(cmp.getFieldCount());
 
-		int tupleCount = buf.getInt(tupleCountOff);
-		int freeSpace = buf.getInt(freeSpaceOff);
+        int tupleCount = buf.getInt(tupleCountOff);
+        int freeSpace = buf.getInt(freeSpaceOff);
 
-		ArrayList<SlotOffTupleOff> sortedTupleOffs = new ArrayList<SlotOffTupleOff>();
-		sortedTupleOffs.ensureCapacity(tupleCount);
-		for (int i = 0; i < tupleCount; i++) {
-			int slotOff = slotManager.getSlotOff(i);
-			int tupleOff = slotManager.getTupleOff(slotOff);
-			sortedTupleOffs.add(new SlotOffTupleOff(i, slotOff, tupleOff));
-		}
-		Collections.sort(sortedTupleOffs);
+        ArrayList<SlotOffTupleOff> sortedTupleOffs = new ArrayList<SlotOffTupleOff>();
+        sortedTupleOffs.ensureCapacity(tupleCount);
+        for (int i = 0; i < tupleCount; i++) {
+            int slotOff = slotManager.getSlotOff(i);
+            int tupleOff = slotManager.getTupleOff(slotOff);
+            sortedTupleOffs.add(new SlotOffTupleOff(i, slotOff, tupleOff));
+        }
+        Collections.sort(sortedTupleOffs);
 
-		for (int i = 0; i < sortedTupleOffs.size(); i++) {
-			int tupleOff = sortedTupleOffs.get(i).tupleOff;
-			frameTuple.resetByTupleOffset(buf, tupleOff);
+        for (int i = 0; i < sortedTupleOffs.size(); i++) {
+            int tupleOff = sortedTupleOffs.get(i).tupleOff;
+            frameTuple.resetByTupleOffset(buf, tupleOff);
 
-			int tupleEndOff = frameTuple.getFieldStart(frameTuple
-					.getFieldCount() - 1)
-					+ frameTuple.getFieldLength(frameTuple.getFieldCount() - 1);
-			int tupleLength = tupleEndOff - tupleOff;
-			System.arraycopy(buf.array(), tupleOff, buf.array(), freeSpace,
-					tupleLength);
+            int tupleEndOff = frameTuple.getFieldStart(frameTuple.getFieldCount() - 1)
+                    + frameTuple.getFieldLength(frameTuple.getFieldCount() - 1);
+            int tupleLength = tupleEndOff - tupleOff;
+            System.arraycopy(buf.array(), tupleOff, buf.array(), freeSpace, tupleLength);
 
-			slotManager.setSlot(sortedTupleOffs.get(i).slotOff, freeSpace);
-			freeSpace += tupleLength;
-		}
+            slotManager.setSlot(sortedTupleOffs.get(i).slotOff, freeSpace);
+            freeSpace += tupleLength;
+        }
 
-		buf.putInt(freeSpaceOff, freeSpace);
-		buf.putInt(totalFreeSpaceOff, buf.capacity() - freeSpace - tupleCount
-				* slotManager.getSlotSize());
+        buf.putInt(freeSpaceOff, freeSpace);
+        buf.putInt(totalFreeSpaceOff, buf.capacity() - freeSpace - tupleCount * slotManager.getSlotSize());
 
-		return false;
-	}
+        return false;
+    }
 
-	@Override
-	public void delete(ITupleReference tuple, MultiComparator cmp,
-			boolean exactDelete) throws Exception {
+    @Override
+    public void delete(ITupleReference tuple, MultiComparator cmp, boolean exactDelete) throws Exception {
 
-		frameTuple.setFieldCount(cmp.getFieldCount());
-		int tupleIndex = slotManager.findTupleIndex(tuple, frameTuple, cmp,
-				FindTupleMode.FTM_EXACT,
-				FindTupleNoExactMatchPolicy.FTP_HIGHER_KEY);
-		int slotOff = slotManager.getSlotOff(tupleIndex);
-		if (tupleIndex < 0) {
-			throw new TreeIndexException("Key to be deleted does not exist.");
-		} else {
-			if (exactDelete) {
-				// check the non-key columns for equality by byte-by-byte
-				// comparison
-				int tupleOff = slotManager.getTupleOff(slotOff);
-				frameTuple.resetByTupleOffset(buf, tupleOff);
+        frameTuple.setFieldCount(cmp.getFieldCount());
+        int tupleIndex = slotManager.findTupleIndex(tuple, frameTuple, cmp, FindTupleMode.FTM_EXACT,
+                FindTupleNoExactMatchPolicy.FTP_HIGHER_KEY);
+        int slotOff = slotManager.getSlotOff(tupleIndex);
+        if (tupleIndex < 0) {
+            throw new TreeIndexException("Key to be deleted does not exist.");
+        } else {
+            if (exactDelete) {
+                // check the non-key columns for equality by byte-by-byte
+                // comparison
+                int tupleOff = slotManager.getTupleOff(slotOff);
+                frameTuple.resetByTupleOffset(buf, tupleOff);
 
-				int comparison = cmp.fieldRangeCompare(tuple, frameTuple,
-						cmp.getKeyFieldCount() - 1,
-						cmp.getFieldCount() - cmp.getKeyFieldCount());
-				if (comparison != 0) {
-					throw new TreeIndexException(
-							"Cannot delete tuple. Byte-by-byte comparison failed to prove equality.");
-				}
-			}
+                int comparison = cmp.fieldRangeCompare(tuple, frameTuple, cmp.getKeyFieldCount() - 1,
+                        cmp.getFieldCount() - cmp.getKeyFieldCount());
+                if (comparison != 0) {
+                    throw new TreeIndexException(
+                            "Cannot delete tuple. Byte-by-byte comparison failed to prove equality.");
+                }
+            }
 
-			int tupleOff = slotManager.getTupleOff(slotOff);
-			frameTuple.resetByTupleOffset(buf, tupleOff);
-			int tupleSize = tupleWriter.bytesRequired(frameTuple);
+            int tupleOff = slotManager.getTupleOff(slotOff);
+            frameTuple.resetByTupleOffset(buf, tupleOff);
+            int tupleSize = tupleWriter.bytesRequired(frameTuple);
 
-			// perform deletion (we just do a memcpy to overwrite the slot)
-			int slotStartOff = slotManager.getSlotEndOff();
-			int length = slotOff - slotStartOff;
-			System.arraycopy(buf.array(), slotStartOff, buf.array(),
-					slotStartOff + slotManager.getSlotSize(), length);
+            // perform deletion (we just do a memcpy to overwrite the slot)
+            int slotStartOff = slotManager.getSlotEndOff();
+            int length = slotOff - slotStartOff;
+            System.arraycopy(buf.array(), slotStartOff, buf.array(), slotStartOff + slotManager.getSlotSize(), length);
 
-			// maintain space information
-			buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) - 1);
-			buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff)
-					+ tupleSize + slotManager.getSlotSize());
-		}
-	}
+            // maintain space information
+            buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) - 1);
+            buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) + tupleSize + slotManager.getSlotSize());
+        }
+    }
 
-	@Override
-	public FrameOpSpaceStatus hasSpaceInsert(ITupleReference tuple,
-			MultiComparator cmp) {
-		int bytesRequired = tupleWriter.bytesRequired(tuple);
-		if (bytesRequired + slotManager.getSlotSize() <= buf.capacity()
-				- buf.getInt(freeSpaceOff)
-				- (buf.getInt(tupleCountOff) * slotManager.getSlotSize()))
-			return FrameOpSpaceStatus.SUFFICIENT_CONTIGUOUS_SPACE;
-		else if (bytesRequired + slotManager.getSlotSize() <= buf
-				.getInt(totalFreeSpaceOff))
-			return FrameOpSpaceStatus.SUFFICIENT_SPACE;
-		else
-			return FrameOpSpaceStatus.INSUFFICIENT_SPACE;
-	}
+    @Override
+    public FrameOpSpaceStatus hasSpaceInsert(ITupleReference tuple, MultiComparator cmp) {
+        int bytesRequired = tupleWriter.bytesRequired(tuple);
+        // Enough space in the contiguous space region?
+        if (bytesRequired + slotManager.getSlotSize() <= buf.capacity() - buf.getInt(freeSpaceOff) 
+                - (buf.getInt(tupleCountOff) * slotManager.getSlotSize())) {
+            return FrameOpSpaceStatus.SUFFICIENT_CONTIGUOUS_SPACE;
+        }
+        // Enough space after compaction?
+        if (bytesRequired + slotManager.getSlotSize() <= buf.getInt(totalFreeSpaceOff)) {
+            return FrameOpSpaceStatus.SUFFICIENT_SPACE;
+        }
+        return FrameOpSpaceStatus.INSUFFICIENT_SPACE;
+    }
 
-	@Override
-	public FrameOpSpaceStatus hasSpaceUpdate(int rid, ITupleReference tuple,
-			MultiComparator cmp) {
-		// TODO Auto-generated method stub
-		return FrameOpSpaceStatus.INSUFFICIENT_SPACE;
-	}
+    @Override
+    public FrameOpSpaceStatus hasSpaceUpdate(ITupleReference newTuple, int oldTupleIndex, MultiComparator cmp) {
+    	frameTuple.resetByTupleIndex(this, oldTupleIndex);
+    	frameTuple.setFieldCount(cmp.getFieldCount());
+    	int oldTupleBytes = frameTuple.getTupleSize();
+    	int newTupleBytes = tupleWriter.bytesRequired(newTuple);
+    	int additionalBytesRequired = newTupleBytes - oldTupleBytes;
+    	// Enough space for an in-place update?
+    	if (additionalBytesRequired <= 0) {
+    		return FrameOpSpaceStatus.SUFFICIENT_INPLACE_SPACE;
+    	}
+    	// Enough space if we delete the old tuple and insert the new one without compaction? 
+    	if (newTupleBytes <= buf.capacity() - buf.getInt(freeSpaceOff)
+                - (buf.getInt(tupleCountOff) * slotManager.getSlotSize())) {
+    		return FrameOpSpaceStatus.SUFFICIENT_CONTIGUOUS_SPACE;
+    	}
+    	// Enough space if we delete the old tuple and compact?
+    	if (additionalBytesRequired <= buf.getInt(totalFreeSpaceOff)) {
+    		return FrameOpSpaceStatus.SUFFICIENT_SPACE;
+    	}
+        return FrameOpSpaceStatus.INSUFFICIENT_SPACE;
+    }
 
-	protected void resetSpaceParams() {
-		buf.putInt(freeSpaceOff, smFlagOff + 1);
-		buf.putInt(totalFreeSpaceOff, buf.capacity() - (smFlagOff + 1));
-	}
+    protected void resetSpaceParams() {
+        buf.putInt(freeSpaceOff, smFlagOff + 1);
+        buf.putInt(totalFreeSpaceOff, buf.capacity() - (smFlagOff + 1));
+    }
 
-	@Override
-	public int findTupleIndex(ITupleReference tuple, MultiComparator cmp)
-			throws Exception {
-		frameTuple.setFieldCount(cmp.getFieldCount());
-		return slotManager.findTupleIndex(tuple, frameTuple, cmp,
-				FindTupleMode.FTM_INCLUSIVE,
-				FindTupleNoExactMatchPolicy.FTP_HIGHER_KEY);
-	}
+    @Override
+    public int findTupleIndex(ITupleReference tuple, MultiComparator cmp, boolean throwIfKeyExists) throws Exception {
+        frameTuple.setFieldCount(cmp.getFieldCount());
+        return slotManager.findTupleIndex(tuple, frameTuple, cmp, FindTupleMode.FTM_INCLUSIVE,
+                FindTupleNoExactMatchPolicy.FTP_HIGHER_KEY);
+    }
 
-	@Override
-	public void insert(ITupleReference tuple, MultiComparator cmp,
-			int tupleIndex) throws Exception {
-		slotManager.insertSlot(tupleIndex, buf.getInt(freeSpaceOff));
-		int bytesWritten = tupleWriter.writeTuple(tuple, buf,
-				buf.getInt(freeSpaceOff));
-		buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
-		buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + bytesWritten);
-		buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff)
-				- bytesWritten - slotManager.getSlotSize());
-	}
+    @Override
+    public void insert(ITupleReference tuple, MultiComparator cmp, int tupleIndex) throws Exception {
+        slotManager.insertSlot(tupleIndex, buf.getInt(freeSpaceOff));
+        int bytesWritten = tupleWriter.writeTuple(tuple, buf.array(), buf.getInt(freeSpaceOff));
+        buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
+        buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + bytesWritten);
+        buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) - bytesWritten - slotManager.getSlotSize());
+    }
 
-	@Override
-	public void update(int rid, ITupleReference tuple) throws Exception {
-		// TODO Auto-generated method stub
+    @Override
+    public void update(ITupleReference newTuple, int oldTupleIndex, boolean inPlace) throws Exception {
+    	frameTuple.resetByTupleIndex(this, oldTupleIndex);
+		int oldTupleBytes = frameTuple.getTupleSize();
+		int slotOff = slotManager.getSlotOff(oldTupleIndex);
+		int bytesWritten = 0;
+    	if (inPlace) {    		
+    		// Overwrite the old tuple in place.
+    		bytesWritten = tupleWriter.writeTuple(newTuple, buf.array(), buf.getInt(slotOff));
+    	} else {
+    		// Insert the new tuple at the end of the free space, and change the slot value (effectively "deleting" the old tuple).
+    		int newTupleOff = buf.getInt(freeSpaceOff);
+    		bytesWritten = tupleWriter.writeTuple(newTuple, buf.array(), newTupleOff);
+    		// Update slot value.
+    		buf.putInt(slotOff, newTupleOff);
+    		// Update contiguous free space pointer.
+    		buf.putInt(freeSpaceOff, newTupleOff + bytesWritten);
+    	}
+    	buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) + oldTupleBytes - bytesWritten);
+    }
 
-	}
+    @Override
+    public void printHeader() {
+        // TODO Auto-generated method stub
 
-	@Override
-	public void printHeader() {
-		// TODO Auto-generated method stub
+    }
 
-	}
+    @Override
+    public int getTupleCount() {
+        return buf.getInt(tupleCountOff);
+    }
 
-	@Override
-	public int getTupleCount() {
-		return buf.getInt(tupleCountOff);
-	}
+    public ISlotManager getSlotManager() {
+        return slotManager;
+    }
 
-	public ISlotManager getSlotManager() {
-		return slotManager;
-	}
+    @Override
+    public String printKeys(MultiComparator cmp, ISerializerDeserializer[] fields) throws HyracksDataException {
+        StringBuilder strBuilder = new StringBuilder();
+        int tupleCount = buf.getInt(tupleCountOff);
+        frameTuple.setFieldCount(fields.length);
+        for (int i = 0; i < tupleCount; i++) {
+            frameTuple.resetByTupleIndex(this, i);
+            for (int j = 0; j < cmp.getKeyFieldCount(); j++) {
+                ByteArrayInputStream inStream = new ByteArrayInputStream(frameTuple.getFieldData(j),
+                        frameTuple.getFieldStart(j), frameTuple.getFieldLength(j));
+                DataInput dataIn = new DataInputStream(inStream);
+                Object o = fields[j].deserialize(dataIn);
+                strBuilder.append(o.toString() + " ");
+            }
+            strBuilder.append(" | ");
+        }
+        strBuilder.append("\n");
+        return strBuilder.toString();
+    }
 
-	@Override
-	public String printKeys(MultiComparator cmp,
-			ISerializerDeserializer[] fields) throws HyracksDataException {
-		StringBuilder strBuilder = new StringBuilder();
-		int tupleCount = buf.getInt(tupleCountOff);
-		frameTuple.setFieldCount(fields.length);
-		for (int i = 0; i < tupleCount; i++) {
-			frameTuple.resetByTupleIndex(this, i);
-			for (int j = 0; j < cmp.getKeyFieldCount(); j++) {
-				ByteArrayInputStream inStream = new ByteArrayInputStream(
-						frameTuple.getFieldData(j),
-						frameTuple.getFieldStart(j),
-						frameTuple.getFieldLength(j));
-				DataInput dataIn = new DataInputStream(inStream);
-				Object o = fields[j].deserialize(dataIn);
-				strBuilder.append(o.toString() + " ");
-			}
-			strBuilder.append(" | ");
-		}
-		strBuilder.append("\n");
-		return strBuilder.toString();
-	}
+    @Override
+    public int getTupleOffset(int slotNum) {
+        return slotManager.getTupleOff(slotManager.getSlotStartOff() - slotNum * slotManager.getSlotSize());
+    }
 
-	@Override
-	public int getTupleOffset(int slotNum) {
-		return slotManager.getTupleOff(slotManager.getSlotStartOff() - slotNum
-				* slotManager.getSlotSize());
-	}
+    @Override
+    public int getPageLsn() {
+        return buf.getInt(pageLsnOff);
+    }
 
-	@Override
-	public int getPageLsn() {
-		return buf.getInt(pageLsnOff);
-	}
+    @Override
+    public void setPageLsn(int pageLsn) {
+        buf.putInt(pageLsnOff, pageLsn);
+    }
 
-	@Override
-	public void setPageLsn(int pageLsn) {
-		buf.putInt(pageLsnOff, pageLsn);
-	}
+    @Override
+    public int getTotalFreeSpace() {
+        return buf.getInt(totalFreeSpaceOff);
+    }
 
-	@Override
-	public int getTotalFreeSpace() {
-		return buf.getInt(totalFreeSpaceOff);
-	}
+    @Override
+    public boolean compress(MultiComparator cmp) {
+        return false;
+    }
 
-	@Override
-	public boolean compress(MultiComparator cmp) {
-		return false;
-	}
+    @Override
+    public int getSlotSize() {
+        return slotManager.getSlotSize();
+    }
 
-	@Override
-	public int getSlotSize() {
-		return slotManager.getSlotSize();
-	}
+    @Override
+    public void setPageTupleFieldCount(int fieldCount) {
+        frameTuple.setFieldCount(fieldCount);
+    }
 
-	@Override
-	public void setPageTupleFieldCount(int fieldCount) {
-		frameTuple.setFieldCount(fieldCount);
-	}
-
-	public ITreeIndexTupleWriter getTupleWriter() {
-		return tupleWriter;
-	}
+    public ITreeIndexTupleWriter getTupleWriter() {
+        return tupleWriter;
+    }
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/SimpleTupleReference.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/SimpleTupleReference.java
index 353bd95..a470d04 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/SimpleTupleReference.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/SimpleTupleReference.java
@@ -22,77 +22,78 @@
 
 public class SimpleTupleReference implements ITreeIndexTupleReference {
 
-	protected ByteBuffer buf;
-	protected int fieldStartIndex;
-	protected int fieldCount;
-	protected int tupleStartOff;
-	protected int nullFlagsBytes;
-	protected int fieldSlotsBytes;
+    protected ByteBuffer buf;
+    protected int fieldStartIndex;
+    protected int fieldCount;
+    protected int tupleStartOff;
+    protected int nullFlagsBytes;
+    protected int fieldSlotsBytes;
+
+    @Override
+    public void resetByTupleOffset(ByteBuffer buf, int tupleStartOff) {
+        this.buf = buf;
+        this.tupleStartOff = tupleStartOff;
+    }
+
+    @Override
+    public void resetByTupleIndex(ITreeIndexFrame frame, int tupleIndex) {
+        resetByTupleOffset(frame.getBuffer(), frame.getTupleOffset(tupleIndex));
+    }
+
+    @Override
+    public void setFieldCount(int fieldCount) {
+        this.fieldCount = fieldCount;
+        nullFlagsBytes = getNullFlagsBytes();
+        fieldSlotsBytes = getFieldSlotsBytes();
+        fieldStartIndex = 0;
+    }
+
+    @Override
+    public void setFieldCount(int fieldStartIndex, int fieldCount) {
+        this.fieldCount = fieldCount;
+        this.fieldStartIndex = fieldStartIndex;
+    }
+
+    @Override
+    public int getFieldCount() {
+        return fieldCount;
+    }
+
+    @Override
+    public byte[] getFieldData(int fIdx) {
+        return buf.array();
+    }
+
+    @Override
+    public int getFieldLength(int fIdx) {
+        if (fIdx == 0) {
+            return buf.getShort(tupleStartOff + nullFlagsBytes);
+        } else {
+            return buf.getShort(tupleStartOff + nullFlagsBytes + fIdx * 2)
+                    - buf.getShort(tupleStartOff + nullFlagsBytes + ((fIdx - 1) * 2));
+        }
+    }
+
+    @Override
+    public int getFieldStart(int fIdx) {
+        if (fIdx == 0) {
+            return tupleStartOff + nullFlagsBytes + fieldSlotsBytes;
+        } else {
+            return tupleStartOff + nullFlagsBytes + fieldSlotsBytes
+                    + buf.getShort(tupleStartOff + nullFlagsBytes + ((fIdx - 1) * 2));
+        }
+    }
+
+    protected int getNullFlagsBytes() {
+        return (int) Math.ceil(fieldCount / 8.0);
+    }
+
+    protected int getFieldSlotsBytes() {
+        return fieldCount * 2;
+    }
 
 	@Override
-	public void resetByTupleOffset(ByteBuffer buf, int tupleStartOff) {
-		this.buf = buf;
-		this.tupleStartOff = tupleStartOff;
-	}
-
-	@Override
-	public void resetByTupleIndex(ITreeIndexFrame frame, int tupleIndex) {
-		resetByTupleOffset(frame.getBuffer(), frame.getTupleOffset(tupleIndex));
-	}
-
-	@Override
-	public void setFieldCount(int fieldCount) {
-		this.fieldCount = fieldCount;
-		nullFlagsBytes = getNullFlagsBytes();
-		fieldSlotsBytes = getFieldSlotsBytes();
-		fieldStartIndex = 0;
-	}
-
-	@Override
-	public void setFieldCount(int fieldStartIndex, int fieldCount) {
-		this.fieldCount = fieldCount;
-		this.fieldStartIndex = fieldStartIndex;
-	}
-
-	@Override
-	public int getFieldCount() {
-		return fieldCount;
-	}
-
-	@Override
-	public byte[] getFieldData(int fIdx) {
-		return buf.array();
-	}
-
-	@Override
-	public int getFieldLength(int fIdx) {
-		if (fIdx == 0) {
-			return buf.getShort(tupleStartOff + nullFlagsBytes);
-		} else {
-			return buf.getShort(tupleStartOff + nullFlagsBytes + fIdx * 2)
-					- buf.getShort(tupleStartOff + nullFlagsBytes
-							+ ((fIdx - 1) * 2));
-		}
-	}
-
-	@Override
-	public int getFieldStart(int fIdx) {
-		if (fIdx == 0) {
-			return tupleStartOff + nullFlagsBytes + fieldSlotsBytes;
-		} else {
-			return tupleStartOff
-					+ nullFlagsBytes
-					+ fieldSlotsBytes
-					+ buf.getShort(tupleStartOff + nullFlagsBytes
-							+ ((fIdx - 1) * 2));
-		}
-	}
-
-	protected int getNullFlagsBytes() {
-		return (int) Math.ceil(fieldCount / 8.0);
-	}
-
-	protected int getFieldSlotsBytes() {
-		return fieldCount * 2;
+	public int getTupleSize() {
+		return nullFlagsBytes + fieldSlotsBytes + buf.getShort(tupleStartOff + nullFlagsBytes + (fieldCount-1) * 2);
 	}
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/SimpleTupleWriter.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/SimpleTupleWriter.java
index 11f7820..831247e 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/SimpleTupleWriter.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/SimpleTupleWriter.java
@@ -23,95 +23,103 @@
 
 public class SimpleTupleWriter implements ITreeIndexTupleWriter {
 
-	@Override
-	public int bytesRequired(ITupleReference tuple) {
-		int bytes = getNullFlagsBytes(tuple) + getFieldSlotsBytes(tuple);
-		for (int i = 0; i < tuple.getFieldCount(); i++) {
-			bytes += tuple.getFieldLength(i);
-		}
-		return bytes;
+	// Write short in little endian to target byte array at given offset.
+	private static void writeShortL(short s, byte[] buf, int targetOff) {
+		buf[targetOff] = (byte)(s >> 8);
+		buf[targetOff + 1] = (byte)(s >> 0);
+	}
+	
+	// Write short in big endian to target byte array at given offset.
+	private static void writeShortB(short s, byte[] buf, int targetOff) {
+		buf[targetOff] = (byte) (s >> 0);
+		buf[targetOff + 1] = (byte) (s >> 8);
+	}
+	
+    @Override
+    public int bytesRequired(ITupleReference tuple) {
+        int bytes = getNullFlagsBytes(tuple) + getFieldSlotsBytes(tuple);
+        for (int i = 0; i < tuple.getFieldCount(); i++) {
+            bytes += tuple.getFieldLength(i);
+        }
+        return bytes;
+    }
+
+    @Override
+    public int bytesRequired(ITupleReference tuple, int startField, int numFields) {
+        int bytes = getNullFlagsBytes(tuple, startField, numFields) + getFieldSlotsBytes(tuple, startField, numFields);
+        for (int i = startField; i < startField + numFields; i++) {
+            bytes += tuple.getFieldLength(i);
+        }
+        return bytes;
+    }
+
+    @Override
+    public ITreeIndexTupleReference createTupleReference() {
+        return new SimpleTupleReference();
+    }
+
+    @Override
+    public int writeTuple(ITupleReference tuple, ByteBuffer targetBuf, int targetOff) {
+        return writeTuple(tuple, targetBuf.array(), targetOff);
+    }
+    
+    @Override
+	public int writeTuple(ITupleReference tuple, byte[] targetBuf, int targetOff) {
+    	int runner = targetOff;
+        int nullFlagsBytes = getNullFlagsBytes(tuple);
+        int fieldSlotsBytes = getFieldSlotsBytes(tuple);
+        for (int i = 0; i < nullFlagsBytes; i++) {
+            targetBuf[runner++] = (byte) 0;
+        }
+        runner += fieldSlotsBytes;
+        int fieldEndOff = 0;
+        for (int i = 0; i < tuple.getFieldCount(); i++) {
+            System.arraycopy(tuple.getFieldData(i), tuple.getFieldStart(i), targetBuf, runner,
+                    tuple.getFieldLength(i));
+            fieldEndOff += tuple.getFieldLength(i);
+            runner += tuple.getFieldLength(i);
+            writeShortL((short) fieldEndOff, targetBuf, targetOff + nullFlagsBytes + i * 2);
+        }
+        return runner - targetOff;
 	}
 
-	@Override
-	public int bytesRequired(ITupleReference tuple, int startField,
-			int numFields) {
-		int bytes = getNullFlagsBytes(tuple, startField, numFields)
-				+ getFieldSlotsBytes(tuple, startField, numFields);
-		for (int i = startField; i < startField + numFields; i++) {
-			bytes += tuple.getFieldLength(i);
-		}
-		return bytes;
-	}
+    @Override
+    public int writeTupleFields(ITupleReference tuple, int startField, int numFields, ByteBuffer targetBuf,
+            int targetOff) {
+        int runner = targetOff;
+        int nullFlagsBytes = getNullFlagsBytes(tuple, startField, numFields);
+        for (int i = 0; i < nullFlagsBytes; i++) {
+            targetBuf.put(runner++, (byte) 0);
+        }
+        runner += getFieldSlotsBytes(tuple, startField, numFields);
 
-	@Override
-	public ITreeIndexTupleReference createTupleReference() {
-		return new SimpleTupleReference();
-	}
+        int fieldEndOff = 0;
+        int fieldCounter = 0;
+        for (int i = startField; i < startField + numFields; i++) {
+            System.arraycopy(tuple.getFieldData(i), tuple.getFieldStart(i), targetBuf.array(), runner,
+                    tuple.getFieldLength(i));
+            fieldEndOff += tuple.getFieldLength(i);
+            runner += tuple.getFieldLength(i);
+            targetBuf.putShort(targetOff + nullFlagsBytes + fieldCounter * 2, (short) fieldEndOff);
+            fieldCounter++;
+        }
 
-	@Override
-	public int writeTuple(ITupleReference tuple, ByteBuffer targetBuf,
-			int targetOff) {
-		int runner = targetOff;
-		int nullFlagsBytes = getNullFlagsBytes(tuple);
-		int fieldSlotsBytes = getFieldSlotsBytes(tuple);
-		for (int i = 0; i < nullFlagsBytes; i++) {
-			targetBuf.put(runner++, (byte) 0);
-		}
-		runner += fieldSlotsBytes;
+        return runner - targetOff;
+    }
 
-		int fieldEndOff = 0;
-		for (int i = 0; i < tuple.getFieldCount(); i++) {
-			System.arraycopy(tuple.getFieldData(i), tuple.getFieldStart(i),
-					targetBuf.array(), runner, tuple.getFieldLength(i));
-			fieldEndOff += tuple.getFieldLength(i);
-			runner += tuple.getFieldLength(i);
-			targetBuf.putShort(targetOff + nullFlagsBytes + i * 2,
-					(short) fieldEndOff);
-		}
+    protected int getNullFlagsBytes(ITupleReference tuple) {
+        return (int) Math.ceil((double) tuple.getFieldCount() / 8.0);
+    }
 
-		return runner - targetOff;
-	}
+    protected int getFieldSlotsBytes(ITupleReference tuple) {
+        return tuple.getFieldCount() * 2;
+    }
 
-	@Override
-	public int writeTupleFields(ITupleReference tuple, int startField,
-			int numFields, ByteBuffer targetBuf, int targetOff) {
-		int runner = targetOff;
-		int nullFlagsBytes = getNullFlagsBytes(tuple, startField, numFields);
-		for (int i = 0; i < nullFlagsBytes; i++) {
-			targetBuf.put(runner++, (byte) 0);
-		}
-		runner += getFieldSlotsBytes(tuple, startField, numFields);
+    protected int getNullFlagsBytes(ITupleReference tuple, int startField, int numFields) {
+        return (int) Math.ceil((double) numFields / 8.0);
+    }
 
-		int fieldEndOff = 0;
-		int fieldCounter = 0;
-		for (int i = startField; i < startField + numFields; i++) {
-			System.arraycopy(tuple.getFieldData(i), tuple.getFieldStart(i),
-					targetBuf.array(), runner, tuple.getFieldLength(i));
-			fieldEndOff += tuple.getFieldLength(i);
-			runner += tuple.getFieldLength(i);
-			targetBuf.putShort(targetOff + nullFlagsBytes + fieldCounter * 2,
-					(short) fieldEndOff);
-			fieldCounter++;
-		}
-
-		return runner - targetOff;
-	}
-
-	protected int getNullFlagsBytes(ITupleReference tuple) {
-		return (int) Math.ceil((double) tuple.getFieldCount() / 8.0);
-	}
-
-	protected int getFieldSlotsBytes(ITupleReference tuple) {
-		return tuple.getFieldCount() * 2;
-	}
-
-	protected int getNullFlagsBytes(ITupleReference tuple, int startField,
-			int numFields) {
-		return (int) Math.ceil((double) numFields / 8.0);
-	}
-
-	protected int getFieldSlotsBytes(ITupleReference tuple, int startField,
-			int numFields) {
-		return numFields * 2;
-	}
+    protected int getFieldSlotsBytes(ITupleReference tuple, int startField, int numFields) {
+        return numFields * 2;
+    }	
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/TypeAwareTupleReference.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/TypeAwareTupleReference.java
index 31b32e6..72a36a1 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/TypeAwareTupleReference.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/TypeAwareTupleReference.java
@@ -22,99 +22,105 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleReference;
 
 public class TypeAwareTupleReference implements ITreeIndexTupleReference {
-	protected ByteBuffer buf;
-	protected int fieldStartIndex;
-	protected int fieldCount;
-	protected int tupleStartOff;
-	protected int nullFlagsBytes;
-	protected int dataStartOff;
+    protected ByteBuffer buf;
+    protected int fieldStartIndex;
+    protected int fieldCount;
+    protected int tupleStartOff;
+    protected int nullFlagsBytes;
+    protected int dataStartOff;
 
-	protected ITypeTrait[] typeTraits;
-	protected VarLenIntEncoderDecoder encDec = new VarLenIntEncoderDecoder();
-	protected int[] decodedFieldSlots;
+    protected ITypeTrait[] typeTraits;
+    protected VarLenIntEncoderDecoder encDec = new VarLenIntEncoderDecoder();
+    protected int[] decodedFieldSlots;
 
-	public TypeAwareTupleReference(ITypeTrait[] typeTraits) {
-		this.typeTraits = typeTraits;
-		this.fieldStartIndex = 0;
-	}
+    public TypeAwareTupleReference(ITypeTrait[] typeTraits) {
+        this.typeTraits = typeTraits;
+        this.fieldStartIndex = 0;
+        setFieldCount(typeTraits.length);
+    }
+
+    @Override
+    public void resetByTupleOffset(ByteBuffer buf, int tupleStartOff) {
+        this.buf = buf;
+        this.tupleStartOff = tupleStartOff;
+
+        // decode field slots
+        int field = 0;
+        int cumul = 0;
+        int end = fieldStartIndex + fieldCount;
+        encDec.reset(buf.array(), tupleStartOff + nullFlagsBytes);
+        for (int i = fieldStartIndex; i < end; i++) {
+            int staticDataLen = typeTraits[i].getStaticallyKnownDataLength();
+            if (staticDataLen == ITypeTrait.VARIABLE_LENGTH) {
+                cumul += encDec.decode();
+                decodedFieldSlots[field++] = cumul;
+            } else {
+                cumul += staticDataLen;
+                decodedFieldSlots[field++] = cumul;
+            }
+        }
+        dataStartOff = encDec.getPos();
+    }
+
+    @Override
+    public void resetByTupleIndex(ITreeIndexFrame frame, int tupleIndex) {
+        resetByTupleOffset(frame.getBuffer(), frame.getTupleOffset(tupleIndex));
+    }
+
+    @Override
+    public void setFieldCount(int fieldCount) {
+        this.fieldCount = fieldCount;
+        if (decodedFieldSlots == null) {
+            decodedFieldSlots = new int[fieldCount];
+        } else {
+            if (fieldCount > decodedFieldSlots.length) {
+                decodedFieldSlots = new int[fieldCount];
+            }
+        }
+        nullFlagsBytes = getNullFlagsBytes();
+        this.fieldStartIndex = 0;
+    }
+
+    @Override
+    public void setFieldCount(int fieldStartIndex, int fieldCount) {
+        setFieldCount(fieldCount);
+        this.fieldStartIndex = fieldStartIndex;
+    }
+
+    @Override
+    public int getFieldCount() {
+        return fieldCount;
+    }
+
+    @Override
+    public byte[] getFieldData(int fIdx) {
+        return buf.array();
+    }
+
+    @Override
+    public int getFieldLength(int fIdx) {
+        if (fIdx == 0) {
+            return decodedFieldSlots[0];
+        } else {
+            return decodedFieldSlots[fIdx] - decodedFieldSlots[fIdx - 1];
+        }
+    }
+
+    @Override
+    public int getFieldStart(int fIdx) {
+        if (fIdx == 0) {
+            return dataStartOff;
+        } else {
+            return dataStartOff + decodedFieldSlots[fIdx - 1];
+        }
+    }
+
+    protected int getNullFlagsBytes() {
+        return (int) Math.ceil(fieldCount / 8.0);
+    }
 
 	@Override
-	public void resetByTupleOffset(ByteBuffer buf, int tupleStartOff) {
-		this.buf = buf;
-		this.tupleStartOff = tupleStartOff;
-
-		// decode field slots
-		int field = 0;
-		int cumul = 0;
-		int end = fieldStartIndex + fieldCount;
-		encDec.reset(buf.array(), tupleStartOff + nullFlagsBytes);
-		for (int i = fieldStartIndex; i < end; i++) {
-			int staticDataLen = typeTraits[i].getStaticallyKnownDataLength();
-			if (staticDataLen == ITypeTrait.VARIABLE_LENGTH) {
-				cumul += encDec.decode();
-				decodedFieldSlots[field++] = cumul;
-			} else {
-				cumul += staticDataLen;
-				decodedFieldSlots[field++] = cumul;
-			}
-		}
-		dataStartOff = encDec.getPos();
-	}
-
-	@Override
-	public void resetByTupleIndex(ITreeIndexFrame frame, int tupleIndex) {
-		resetByTupleOffset(frame.getBuffer(), frame.getTupleOffset(tupleIndex));
-	}
-
-	@Override
-	public void setFieldCount(int fieldCount) {
-		this.fieldCount = fieldCount;
-		if (decodedFieldSlots == null) {
-			decodedFieldSlots = new int[fieldCount];
-		} else {
-			if (fieldCount > decodedFieldSlots.length) {
-				decodedFieldSlots = new int[fieldCount];
-			}
-		}
-		nullFlagsBytes = getNullFlagsBytes();
-		this.fieldStartIndex = 0;
-	}
-
-	@Override
-	public void setFieldCount(int fieldStartIndex, int fieldCount) {
-		setFieldCount(fieldCount);
-		this.fieldStartIndex = fieldStartIndex;
-	}
-
-	@Override
-	public int getFieldCount() {
-		return fieldCount;
-	}
-
-	@Override
-	public byte[] getFieldData(int fIdx) {
-		return buf.array();
-	}
-
-	@Override
-	public int getFieldLength(int fIdx) {
-		if (fIdx == 0) {
-			return decodedFieldSlots[0];
-		} else {
-			return decodedFieldSlots[fIdx] - decodedFieldSlots[fIdx - 1];
-		}
-	}
-
-	@Override
-	public int getFieldStart(int fIdx) {
-		if (fIdx == 0) {
-			return dataStartOff;
-		} else {
-			return dataStartOff + decodedFieldSlots[fIdx - 1];
-		}
-	}
-
-	protected int getNullFlagsBytes() {
-		return (int) Math.ceil(fieldCount / 8.0);
+	public int getTupleSize() {
+		return dataStartOff - tupleStartOff + decodedFieldSlots[fieldCount-1];
 	}
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/TypeAwareTupleWriter.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/TypeAwareTupleWriter.java
index 95468d4..56c4d10 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/TypeAwareTupleWriter.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/tuples/TypeAwareTupleWriter.java
@@ -24,131 +24,130 @@
 
 public class TypeAwareTupleWriter implements ITreeIndexTupleWriter {
 
-	protected ITypeTrait[] typeTraits;
-	protected VarLenIntEncoderDecoder encDec = new VarLenIntEncoderDecoder();
+    protected ITypeTrait[] typeTraits;
+    protected VarLenIntEncoderDecoder encDec = new VarLenIntEncoderDecoder();
 
-	public TypeAwareTupleWriter(ITypeTrait[] typeTraits) {
-		this.typeTraits = typeTraits;
-	}
+    public TypeAwareTupleWriter(ITypeTrait[] typeTraits) {
+        this.typeTraits = typeTraits;
+    }
 
-	@Override
-	public int bytesRequired(ITupleReference tuple) {
-		int bytes = getNullFlagsBytes(tuple) + getFieldSlotsBytes(tuple);
-		for (int i = 0; i < tuple.getFieldCount(); i++) {
-			bytes += tuple.getFieldLength(i);
-		}
-		return bytes;
-	}
+    @Override
+    public int bytesRequired(ITupleReference tuple) {
+        int bytes = getNullFlagsBytes(tuple) + getFieldSlotsBytes(tuple);
+        for (int i = 0; i < tuple.getFieldCount(); i++) {
+            bytes += tuple.getFieldLength(i);
+        }
+        return bytes;
+    }
 
-	@Override
-	public int bytesRequired(ITupleReference tuple, int startField,
-			int numFields) {
-		int bytes = getNullFlagsBytes(numFields)
-				+ getFieldSlotsBytes(tuple, startField, numFields);
-		for (int i = startField; i < startField + numFields; i++) {
-			bytes += tuple.getFieldLength(i);
-		}
-		return bytes;
-	}
+    @Override
+    public int bytesRequired(ITupleReference tuple, int startField, int numFields) {
+        int bytes = getNullFlagsBytes(numFields) + getFieldSlotsBytes(tuple, startField, numFields);
+        for (int i = startField; i < startField + numFields; i++) {
+            bytes += tuple.getFieldLength(i);
+        }
+        return bytes;
+    }
 
-	@Override
-	public ITreeIndexTupleReference createTupleReference() {
-		return new TypeAwareTupleReference(typeTraits);
-	}
+    @Override
+    public ITreeIndexTupleReference createTupleReference() {
+        return new TypeAwareTupleReference(typeTraits);
+    }
 
-	@Override
-	public int writeTuple(ITupleReference tuple, ByteBuffer targetBuf,
-			int targetOff) {
-		int runner = targetOff;
-		int nullFlagsBytes = getNullFlagsBytes(tuple);
-		// write null indicator bits
-		for (int i = 0; i < nullFlagsBytes; i++) {
-			targetBuf.put(runner++, (byte) 0);
-		}
+    @Override
+    public int writeTuple(ITupleReference tuple, ByteBuffer targetBuf, int targetOff) {
+        return writeTuple(tuple, targetBuf.array(), targetOff);
+    }
 
-		// write field slots for variable length fields
-		encDec.reset(targetBuf.array(), runner);
-		for (int i = 0; i < tuple.getFieldCount(); i++) {
-			if (typeTraits[i].getStaticallyKnownDataLength() == ITypeTrait.VARIABLE_LENGTH) {
-				encDec.encode(tuple.getFieldLength(i));
-			}
-		}
-		runner = encDec.getPos();
+    @Override
+    public int writeTuple(ITupleReference tuple, byte[] targetBuf, int targetOff) {
+        int runner = targetOff;
+        int nullFlagsBytes = getNullFlagsBytes(tuple);
+        // write null indicator bits
+        for (int i = 0; i < nullFlagsBytes; i++) {
+        	targetBuf[runner++] = (byte) 0;
+        }
 
-		// write data fields
-		for (int i = 0; i < tuple.getFieldCount(); i++) {
-			System.arraycopy(tuple.getFieldData(i), tuple.getFieldStart(i),
-					targetBuf.array(), runner, tuple.getFieldLength(i));
-			runner += tuple.getFieldLength(i);
-		}
+        // write field slots for variable length fields
+        encDec.reset(targetBuf, runner);
+        for (int i = 0; i < tuple.getFieldCount(); i++) {
+            if (typeTraits[i].getStaticallyKnownDataLength() == ITypeTrait.VARIABLE_LENGTH) {
+                encDec.encode(tuple.getFieldLength(i));
+            }
+        }
+        runner = encDec.getPos();
 
-		return runner - targetOff;
-	}
+        // write data fields
+        for (int i = 0; i < tuple.getFieldCount(); i++) {
+            System.arraycopy(tuple.getFieldData(i), tuple.getFieldStart(i), targetBuf, runner,
+                    tuple.getFieldLength(i));
+            runner += tuple.getFieldLength(i);
+        }
 
-	@Override
-	public int writeTupleFields(ITupleReference tuple, int startField,
-			int numFields, ByteBuffer targetBuf, int targetOff) {
-		int runner = targetOff;
-		int nullFlagsBytes = getNullFlagsBytes(numFields);
-		// write null indicator bits
-		for (int i = 0; i < nullFlagsBytes; i++) {
-			targetBuf.put(runner++, (byte) 0);
-		}
+        return runner - targetOff;
+    }
+    
+    @Override
+    public int writeTupleFields(ITupleReference tuple, int startField, int numFields, ByteBuffer targetBuf,
+            int targetOff) {
+        int runner = targetOff;
+        int nullFlagsBytes = getNullFlagsBytes(numFields);
+        // write null indicator bits
+        for (int i = 0; i < nullFlagsBytes; i++) {
+            targetBuf.put(runner++, (byte) 0);
+        }
 
-		// write field slots for variable length fields
-		encDec.reset(targetBuf.array(), runner);
-		for (int i = startField; i < startField + numFields; i++) {
-			if (typeTraits[i].getStaticallyKnownDataLength() == ITypeTrait.VARIABLE_LENGTH) {
-				encDec.encode(tuple.getFieldLength(i));
-			}
-		}
-		runner = encDec.getPos();
+        // write field slots for variable length fields
+        encDec.reset(targetBuf.array(), runner);
+        for (int i = startField; i < startField + numFields; i++) {
+            if (typeTraits[i].getStaticallyKnownDataLength() == ITypeTrait.VARIABLE_LENGTH) {
+                encDec.encode(tuple.getFieldLength(i));
+            }
+        }
+        runner = encDec.getPos();
 
-		for (int i = startField; i < startField + numFields; i++) {
-			System.arraycopy(tuple.getFieldData(i), tuple.getFieldStart(i),
-					targetBuf.array(), runner, tuple.getFieldLength(i));
-			runner += tuple.getFieldLength(i);
-		}
+        for (int i = startField; i < startField + numFields; i++) {
+            System.arraycopy(tuple.getFieldData(i), tuple.getFieldStart(i), targetBuf.array(), runner,
+                    tuple.getFieldLength(i));
+            runner += tuple.getFieldLength(i);
+        }
 
-		return runner - targetOff;
-	}
+        return runner - targetOff;
+    }
 
-	protected int getNullFlagsBytes(ITupleReference tuple) {
-		return (int) Math.ceil((double) tuple.getFieldCount() / 8.0);
-	}
+    protected int getNullFlagsBytes(ITupleReference tuple) {
+        return (int) Math.ceil((double) tuple.getFieldCount() / 8.0);
+    }
 
-	protected int getFieldSlotsBytes(ITupleReference tuple) {
-		int fieldSlotBytes = 0;
-		for (int i = 0; i < tuple.getFieldCount(); i++) {
-			if (typeTraits[i].getStaticallyKnownDataLength() == ITypeTrait.VARIABLE_LENGTH) {
-				fieldSlotBytes += encDec.getBytesRequired(tuple
-						.getFieldLength(i));
-			}
-		}
-		return fieldSlotBytes;
-	}
+    protected int getFieldSlotsBytes(ITupleReference tuple) {
+        int fieldSlotBytes = 0;
+        for (int i = 0; i < tuple.getFieldCount(); i++) {
+            if (typeTraits[i].getStaticallyKnownDataLength() == ITypeTrait.VARIABLE_LENGTH) {
+                fieldSlotBytes += encDec.getBytesRequired(tuple.getFieldLength(i));
+            }
+        }
+        return fieldSlotBytes;
+    }
 
-	protected int getNullFlagsBytes(int numFields) {
-		return (int) Math.ceil((double) numFields / 8.0);
-	}
+    protected int getNullFlagsBytes(int numFields) {
+        return (int) Math.ceil((double) numFields / 8.0);
+    }
 
-	protected int getFieldSlotsBytes(ITupleReference tuple, int startField,
-			int numFields) {
-		int fieldSlotBytes = 0;
-		for (int i = startField; i < startField + numFields; i++) {
-			if (typeTraits[i].getStaticallyKnownDataLength() == ITypeTrait.VARIABLE_LENGTH) {
-				fieldSlotBytes += encDec.getBytesRequired(tuple
-						.getFieldLength(i));
-			}
-		}
-		return fieldSlotBytes;
-	}
+    protected int getFieldSlotsBytes(ITupleReference tuple, int startField, int numFields) {
+        int fieldSlotBytes = 0;
+        for (int i = startField; i < startField + numFields; i++) {
+            if (typeTraits[i].getStaticallyKnownDataLength() == ITypeTrait.VARIABLE_LENGTH) {
+                fieldSlotBytes += encDec.getBytesRequired(tuple.getFieldLength(i));
+            }
+        }
+        return fieldSlotBytes;
+    }
 
-	public ITypeTrait[] getTypeTraits() {
-		return typeTraits;
-	}
+    public ITypeTrait[] getTypeTraits() {
+        return typeTraits;
+    }
 
-	public void setTypeTraits(ITypeTrait[] typeTraits) {
-		this.typeTraits = typeTraits;
-	}
+    public void setTypeTraits(ITypeTrait[] typeTraits) {
+        this.typeTraits = typeTraits;
+    }
 }
diff --git a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMInteriorFrame.java b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMInteriorFrame.java
index 38d2a46..18c0d38 100644
--- a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMInteriorFrame.java
+++ b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMInteriorFrame.java
@@ -40,685 +40,603 @@
 import edu.uci.ics.hyracks.storage.am.rtree.impls.UnorderedSlotManager;
 import edu.uci.ics.hyracks.storage.am.rtree.tuples.RTreeTypeAwareTupleWriter;
 
-public class RTreeNSMInteriorFrame extends RTreeNSMFrame implements
-		IRTreeInteriorFrame {
+public class RTreeNSMInteriorFrame extends RTreeNSMFrame implements IRTreeInteriorFrame {
 
-	private static final int childPtrSize = 4;
+    private static final int childPtrSize = 4;
 
-	public RTreeNSMInteriorFrame(ITreeIndexTupleWriter tupleWriter,
-			int keyFieldCount) {
-		super(tupleWriter, keyFieldCount);
-	}
+    public RTreeNSMInteriorFrame(ITreeIndexTupleWriter tupleWriter, int keyFieldCount) {
+        super(tupleWriter, keyFieldCount);
+    }
 
-	@Override
-	public String printKeys(MultiComparator cmp,
-			ISerializerDeserializer[] fields) throws HyracksDataException {
-		StringBuilder strBuilder = new StringBuilder();
-		int tupleCount = buf.getInt(tupleCountOff);
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
-		for (int i = 0; i < tupleCount; i++) {
-			frameTuple.resetByTupleIndex(this, i);
-			for (int j = 0; j < cmp.getKeyFieldCount(); j++) {
-				ByteArrayInputStream inStream = new ByteArrayInputStream(
-						frameTuple.getFieldData(j),
-						frameTuple.getFieldStart(j),
-						frameTuple.getFieldLength(j));
-				DataInput dataIn = new DataInputStream(inStream);
-				Object o = fields[j].deserialize(dataIn);
-				strBuilder.append(o.toString() + " ");
-			}
-			strBuilder.append(" | ");
-		}
-		strBuilder.append("\n");
-		return strBuilder.toString();
-	}
+    @Override
+    public String printKeys(MultiComparator cmp, ISerializerDeserializer[] fields) throws HyracksDataException {
+        StringBuilder strBuilder = new StringBuilder();
+        int tupleCount = buf.getInt(tupleCountOff);
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
+        for (int i = 0; i < tupleCount; i++) {
+            frameTuple.resetByTupleIndex(this, i);
+            for (int j = 0; j < cmp.getKeyFieldCount(); j++) {
+                ByteArrayInputStream inStream = new ByteArrayInputStream(frameTuple.getFieldData(j),
+                        frameTuple.getFieldStart(j), frameTuple.getFieldLength(j));
+                DataInput dataIn = new DataInputStream(inStream);
+                Object o = fields[j].deserialize(dataIn);
+                strBuilder.append(o.toString() + " ");
+            }
+            strBuilder.append(" | ");
+        }
+        strBuilder.append("\n");
+        return strBuilder.toString();
+    }
 
-	@Override
-	public boolean findBestChild(ITupleReference tuple, MultiComparator cmp) {
-		cmpFrameTuple.setFieldCount(cmp.getKeyFieldCount());
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
+    @Override
+    public boolean findBestChild(ITupleReference tuple, MultiComparator cmp) {
+        cmpFrameTuple.setFieldCount(cmp.getKeyFieldCount());
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
 
-		int bestChild = 0;
-		double minEnlargedArea = Double.MAX_VALUE;
+        int bestChild = 0;
+        double minEnlargedArea = Double.MAX_VALUE;
 
-		// the children pointers in the node point to leaves
-		if (getLevel() == 1) {
-			// find least overlap enlargement, use minimum enlarged area to
-			// break tie, if tie still exists use minimum area to break it
-			for (int i = 0; i < getTupleCount(); ++i) {
-				frameTuple.resetByTupleIndex(this, i);
-				double enlargedArea = enlargedArea(frameTuple, tuple, cmp);
-				tupleEntries1.add(i, enlargedArea);
-				if (enlargedArea < minEnlargedArea) {
-					minEnlargedArea = enlargedArea;
-					bestChild = i;
-				}
-			}
-			if (minEnlargedArea < RTreeNSMFrame.doubleEpsilon()
-					|| minEnlargedArea > RTreeNSMFrame.doubleEpsilon()) {
-				minEnlargedArea = Double.MAX_VALUE;
-				int k;
-				if (getTupleCount() > nearMinimumOverlapFactor) {
-					// sort the entries based on their area enlargement needed
-					// to include the object
-					tupleEntries1.sort(EntriesOrder.ASCENDING, getTupleCount());
-					k = nearMinimumOverlapFactor;
-				} else {
-					k = getTupleCount();
-				}
+        // the children pointers in the node point to leaves
+        if (getLevel() == 1) {
+            // find least overlap enlargement, use minimum enlarged area to
+            // break tie, if tie still exists use minimum area to break it
+            for (int i = 0; i < getTupleCount(); ++i) {
+                frameTuple.resetByTupleIndex(this, i);
+                double enlargedArea = enlargedArea(frameTuple, tuple, cmp);
+                tupleEntries1.add(i, enlargedArea);
+                if (enlargedArea < minEnlargedArea) {
+                    minEnlargedArea = enlargedArea;
+                    bestChild = i;
+                }
+            }
+            if (minEnlargedArea < RTreeNSMFrame.doubleEpsilon() || minEnlargedArea > RTreeNSMFrame.doubleEpsilon()) {
+                minEnlargedArea = Double.MAX_VALUE;
+                int k;
+                if (getTupleCount() > nearMinimumOverlapFactor) {
+                    // sort the entries based on their area enlargement needed
+                    // to include the object
+                    tupleEntries1.sort(EntriesOrder.ASCENDING, getTupleCount());
+                    k = nearMinimumOverlapFactor;
+                } else {
+                    k = getTupleCount();
+                }
 
-				double minOverlap = Double.MAX_VALUE;
-				int id = 0;
-				for (int i = 0; i < k; ++i) {
-					double difference = 0.0;
-					for (int j = 0; j < getTupleCount(); ++j) {
-						frameTuple.resetByTupleIndex(this, j);
-						cmpFrameTuple.resetByTupleIndex(this, tupleEntries1
-								.get(i).getTupleIndex());
+                double minOverlap = Double.MAX_VALUE;
+                int id = 0;
+                for (int i = 0; i < k; ++i) {
+                    double difference = 0.0;
+                    for (int j = 0; j < getTupleCount(); ++j) {
+                        frameTuple.resetByTupleIndex(this, j);
+                        cmpFrameTuple.resetByTupleIndex(this, tupleEntries1.get(i).getTupleIndex());
 
-						int c = pointerCmp(frameTuple, cmpFrameTuple, cmp);
-						if (c != 0) {
-							double intersection = overlappedArea(frameTuple,
-									tuple, cmpFrameTuple, cmp);
-							if (intersection != 0.0) {
-								difference += intersection
-										- overlappedArea(frameTuple, null,
-												cmpFrameTuple, cmp);
-							}
-						} else {
-							id = j;
-						}
-					}
+                        int c = pointerCmp(frameTuple, cmpFrameTuple, cmp);
+                        if (c != 0) {
+                            double intersection = overlappedArea(frameTuple, tuple, cmpFrameTuple, cmp);
+                            if (intersection != 0.0) {
+                                difference += intersection - overlappedArea(frameTuple, null, cmpFrameTuple, cmp);
+                            }
+                        } else {
+                            id = j;
+                        }
+                    }
 
-					double enlargedArea = enlargedArea(cmpFrameTuple, tuple,
-							cmp);
-					if (difference < minOverlap) {
-						minOverlap = difference;
-						minEnlargedArea = enlargedArea;
-						bestChild = id;
-					} else if (difference == minOverlap) {
-						if (enlargedArea < minEnlargedArea) {
-							minEnlargedArea = enlargedArea;
-							bestChild = id;
-						} else if (enlargedArea == minEnlargedArea) {
-							double area = area(cmpFrameTuple, cmp);
-							frameTuple.resetByTupleIndex(this, bestChild);
-							double minArea = area(frameTuple, cmp);
-							if (area < minArea) {
-								bestChild = id;
-							}
-						}
-					}
-				}
-			}
-		} else { // find minimum enlarged area, use minimum area to break tie
-			for (int i = 0; i < getTupleCount(); i++) {
-				frameTuple.resetByTupleIndex(this, i);
-				double enlargedArea = enlargedArea(frameTuple, tuple, cmp);
-				if (enlargedArea < minEnlargedArea) {
-					minEnlargedArea = enlargedArea;
-					bestChild = i;
-				} else if (enlargedArea == minEnlargedArea) {
-					double area = area(frameTuple, cmp);
-					frameTuple.resetByTupleIndex(this, bestChild);
-					double minArea = area(frameTuple, cmp);
-					if (area < minArea) {
-						bestChild = i;
-					}
-				}
-			}
-		}
-		tupleEntries1.clear();
+                    double enlargedArea = enlargedArea(cmpFrameTuple, tuple, cmp);
+                    if (difference < minOverlap) {
+                        minOverlap = difference;
+                        minEnlargedArea = enlargedArea;
+                        bestChild = id;
+                    } else if (difference == minOverlap) {
+                        if (enlargedArea < minEnlargedArea) {
+                            minEnlargedArea = enlargedArea;
+                            bestChild = id;
+                        } else if (enlargedArea == minEnlargedArea) {
+                            double area = area(cmpFrameTuple, cmp);
+                            frameTuple.resetByTupleIndex(this, bestChild);
+                            double minArea = area(frameTuple, cmp);
+                            if (area < minArea) {
+                                bestChild = id;
+                            }
+                        }
+                    }
+                }
+            }
+        } else { // find minimum enlarged area, use minimum area to break tie
+            for (int i = 0; i < getTupleCount(); i++) {
+                frameTuple.resetByTupleIndex(this, i);
+                double enlargedArea = enlargedArea(frameTuple, tuple, cmp);
+                if (enlargedArea < minEnlargedArea) {
+                    minEnlargedArea = enlargedArea;
+                    bestChild = i;
+                } else if (enlargedArea == minEnlargedArea) {
+                    double area = area(frameTuple, cmp);
+                    frameTuple.resetByTupleIndex(this, bestChild);
+                    double minArea = area(frameTuple, cmp);
+                    if (area < minArea) {
+                        bestChild = i;
+                    }
+                }
+            }
+        }
+        tupleEntries1.clear();
 
-		frameTuple.resetByTupleIndex(this, bestChild);
-		if (minEnlargedArea > 0.0) {
-			return true;
-		} else {
-			return false;
-		}
-	}
+        frameTuple.resetByTupleIndex(this, bestChild);
+        if (minEnlargedArea > 0.0) {
+            return true;
+        } else {
+            return false;
+        }
+    }
 
-	@Override
-	public int getBestChildPageId(MultiComparator cmp) {
-		return buf.getInt(getChildPointerOff(frameTuple, cmp));
-	}
+    @Override
+    public int getBestChildPageId(MultiComparator cmp) {
+        return buf.getInt(getChildPointerOff(frameTuple, cmp));
+    }
 
-	@Override
-	public int findTupleByPointer(ITupleReference tuple, MultiComparator cmp) {
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
-		for (int i = 0; i < getTupleCount(); i++) {
-			frameTuple.resetByTupleIndex(this, i);
-			int c = pointerCmp(frameTuple, tuple, cmp);
-			if (c == 0) {
-				return i;
-			}
-		}
-		return -1;
-	}
+    @Override
+    public int findTupleByPointer(ITupleReference tuple, MultiComparator cmp) {
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
+        for (int i = 0; i < getTupleCount(); i++) {
+            frameTuple.resetByTupleIndex(this, i);
+            int c = pointerCmp(frameTuple, tuple, cmp);
+            if (c == 0) {
+                return i;
+            }
+        }
+        return -1;
+    }
 
-	@Override
-	public int getChildPageIdIfIntersect(ITupleReference tuple, int tupleIndex,
-			MultiComparator cmp) {
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
-		frameTuple.resetByTupleIndex(this, tupleIndex);
-		int maxFieldPos = cmp.getKeyFieldCount() / 2;
-		for (int i = 0; i < maxFieldPos; i++) {
-			int j = maxFieldPos + i;
-			int c = cmp.getComparators()[i].compare(tuple.getFieldData(i),
-					tuple.getFieldStart(i), tuple.getFieldLength(i),
-					frameTuple.getFieldData(j), frameTuple.getFieldStart(j),
-					frameTuple.getFieldLength(j));
-			if (c > 0) {
-				return -1;
-			}
-			c = cmp.getComparators()[i].compare(tuple.getFieldData(j),
-					tuple.getFieldStart(j), tuple.getFieldLength(j),
-					frameTuple.getFieldData(i), frameTuple.getFieldStart(i),
-					frameTuple.getFieldLength(i));
-			if (c < 0) {
-				return -1;
-			}
-		}
-		return buf.getInt(getChildPointerOff(frameTuple, cmp));
-	}
+    @Override
+    public int getChildPageIdIfIntersect(ITupleReference tuple, int tupleIndex, MultiComparator cmp) {
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
+        frameTuple.resetByTupleIndex(this, tupleIndex);
+        int maxFieldPos = cmp.getKeyFieldCount() / 2;
+        for (int i = 0; i < maxFieldPos; i++) {
+            int j = maxFieldPos + i;
+            int c = cmp.getComparators()[i].compare(tuple.getFieldData(i), tuple.getFieldStart(i),
+                    tuple.getFieldLength(i), frameTuple.getFieldData(j), frameTuple.getFieldStart(j),
+                    frameTuple.getFieldLength(j));
+            if (c > 0) {
+                return -1;
+            }
+            c = cmp.getComparators()[i].compare(tuple.getFieldData(j), tuple.getFieldStart(j), tuple.getFieldLength(j),
+                    frameTuple.getFieldData(i), frameTuple.getFieldStart(i), frameTuple.getFieldLength(i));
+            if (c < 0) {
+                return -1;
+            }
+        }
+        return buf.getInt(getChildPointerOff(frameTuple, cmp));
+    }
 
-	@Override
-	public int findTupleByPointer(ITupleReference tuple, PathList traverseList,
-			int parentIndex, MultiComparator cmp) {
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
-		for (int i = 0; i < getTupleCount(); i++) {
-			frameTuple.resetByTupleIndex(this, i);
+    @Override
+    public int findTupleByPointer(ITupleReference tuple, PathList traverseList, int parentIndex, MultiComparator cmp) {
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
+        for (int i = 0; i < getTupleCount(); i++) {
+            frameTuple.resetByTupleIndex(this, i);
 
-			int c = pointerCmp(frameTuple, tuple, cmp);
-			if (c == 0) {
-				return i;
-			} else {
-				int pageId = IntegerSerializerDeserializer.getInt(
-						frameTuple.getFieldData(cmp.getKeyFieldCount() - 1),
-						getChildPointerOff(frameTuple, cmp));
-				traverseList.add(pageId, -1, parentIndex);
-			}
-		}
-		return -1;
-	}
+            int c = pointerCmp(frameTuple, tuple, cmp);
+            if (c == 0) {
+                return i;
+            } else {
+                int pageId = IntegerSerializerDeserializer.getInt(frameTuple.getFieldData(cmp.getKeyFieldCount() - 1),
+                        getChildPointerOff(frameTuple, cmp));
+                traverseList.add(pageId, -1, parentIndex);
+            }
+        }
+        return -1;
+    }
 
-	@Override
-	public boolean compact(MultiComparator cmp) {
-		resetSpaceParams();
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
+    @Override
+    public boolean compact(MultiComparator cmp) {
+        resetSpaceParams();
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
 
-		int tupleCount = buf.getInt(tupleCountOff);
-		int freeSpace = buf.getInt(freeSpaceOff);
+        int tupleCount = buf.getInt(tupleCountOff);
+        int freeSpace = buf.getInt(freeSpaceOff);
 
-		ArrayList<SlotOffTupleOff> sortedTupleOffs = new ArrayList<SlotOffTupleOff>();
-		sortedTupleOffs.ensureCapacity(tupleCount);
-		for (int i = 0; i < tupleCount; i++) {
-			int slotOff = slotManager.getSlotOff(i);
-			int tupleOff = slotManager.getTupleOff(slotOff);
-			sortedTupleOffs.add(new SlotOffTupleOff(i, slotOff, tupleOff));
-		}
-		Collections.sort(sortedTupleOffs);
+        ArrayList<SlotOffTupleOff> sortedTupleOffs = new ArrayList<SlotOffTupleOff>();
+        sortedTupleOffs.ensureCapacity(tupleCount);
+        for (int i = 0; i < tupleCount; i++) {
+            int slotOff = slotManager.getSlotOff(i);
+            int tupleOff = slotManager.getTupleOff(slotOff);
+            sortedTupleOffs.add(new SlotOffTupleOff(i, slotOff, tupleOff));
+        }
+        Collections.sort(sortedTupleOffs);
 
-		for (int i = 0; i < sortedTupleOffs.size(); i++) {
-			int tupleOff = sortedTupleOffs.get(i).tupleOff;
-			frameTuple.resetByTupleOffset(buf, tupleOff);
+        for (int i = 0; i < sortedTupleOffs.size(); i++) {
+            int tupleOff = sortedTupleOffs.get(i).tupleOff;
+            frameTuple.resetByTupleOffset(buf, tupleOff);
 
-			int tupleEndOff = frameTuple.getFieldStart(frameTuple
-					.getFieldCount() - 1)
-					+ frameTuple.getFieldLength(frameTuple.getFieldCount() - 1);
-			int tupleLength = tupleEndOff - tupleOff + childPtrSize;
-			System.arraycopy(buf.array(), tupleOff, buf.array(), freeSpace,
-					tupleLength);
+            int tupleEndOff = frameTuple.getFieldStart(frameTuple.getFieldCount() - 1)
+                    + frameTuple.getFieldLength(frameTuple.getFieldCount() - 1);
+            int tupleLength = tupleEndOff - tupleOff + childPtrSize;
+            System.arraycopy(buf.array(), tupleOff, buf.array(), freeSpace, tupleLength);
 
-			slotManager.setSlot(sortedTupleOffs.get(i).slotOff, freeSpace);
-			freeSpace += tupleLength;
-		}
+            slotManager.setSlot(sortedTupleOffs.get(i).slotOff, freeSpace);
+            freeSpace += tupleLength;
+        }
 
-		buf.putInt(freeSpaceOff, freeSpace);
-		buf.putInt(totalFreeSpaceOff, buf.capacity() - freeSpace - tupleCount
-				* slotManager.getSlotSize());
+        buf.putInt(freeSpaceOff, freeSpace);
+        buf.putInt(totalFreeSpaceOff, buf.capacity() - freeSpace - tupleCount * slotManager.getSlotSize());
 
-		return false;
-	}
+        return false;
+    }
 
-	@Override
-	public FrameOpSpaceStatus hasSpaceInsert(ITupleReference tuple,
-			MultiComparator cmp) {
-		int bytesRequired = tupleWriter.bytesRequired(tuple) + childPtrSize; // for
-																				// the
-																				// child
-																				// pointer
-		if (bytesRequired + slotManager.getSlotSize() <= buf.capacity()
-				- buf.getInt(freeSpaceOff)
-				- (buf.getInt(tupleCountOff) * slotManager.getSlotSize()))
-			return FrameOpSpaceStatus.SUFFICIENT_CONTIGUOUS_SPACE;
-		else if (bytesRequired + slotManager.getSlotSize() <= buf
-				.getInt(totalFreeSpaceOff))
-			return FrameOpSpaceStatus.SUFFICIENT_SPACE;
-		else
-			return FrameOpSpaceStatus.INSUFFICIENT_SPACE;
-	}
+    @Override
+    public FrameOpSpaceStatus hasSpaceInsert(ITupleReference tuple, MultiComparator cmp) {
+        int bytesRequired = tupleWriter.bytesRequired(tuple) + childPtrSize; // for
+                                                                             // the
+                                                                             // child
+                                                                             // pointer
+        if (bytesRequired + slotManager.getSlotSize() <= buf.capacity() - buf.getInt(freeSpaceOff)
+                - (buf.getInt(tupleCountOff) * slotManager.getSlotSize()))
+            return FrameOpSpaceStatus.SUFFICIENT_CONTIGUOUS_SPACE;
+        else if (bytesRequired + slotManager.getSlotSize() <= buf.getInt(totalFreeSpaceOff))
+            return FrameOpSpaceStatus.SUFFICIENT_SPACE;
+        else
+            return FrameOpSpaceStatus.INSUFFICIENT_SPACE;
+    }
 
-	@Override
-	public void adjustKey(ITupleReference tuple, int tupleIndex,
-			MultiComparator cmp) {
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
-		if (tupleIndex == -1) {
-			tupleIndex = findTupleByPointer(tuple, cmp);
-		}
-		if (tupleIndex != -1) {
-			tupleWriter.writeTuple(tuple, buf, getTupleOffset(tupleIndex));
-		}
-	}
+    @Override
+    public void adjustKey(ITupleReference tuple, int tupleIndex, MultiComparator cmp) {
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
+        if (tupleIndex == -1) {
+            tupleIndex = findTupleByPointer(tuple, cmp);
+        }
+        if (tupleIndex != -1) {
+            tupleWriter.writeTuple(tuple, buf.array(), getTupleOffset(tupleIndex));
+        }
+    }
 
-	private int pointerCmp(ITupleReference tupleA, ITupleReference tupleB,
-			MultiComparator cmp) {
-		return cmp.getIntCmp().compare(
-				tupleA.getFieldData(cmp.getKeyFieldCount() - 1),
-				getChildPointerOff(tupleA, cmp), childPtrSize,
-				tupleB.getFieldData(cmp.getKeyFieldCount() - 1),
-				getChildPointerOff(tupleB, cmp), childPtrSize);
-	}
+    private int pointerCmp(ITupleReference tupleA, ITupleReference tupleB, MultiComparator cmp) {
+        return cmp.getIntCmp().compare(tupleA.getFieldData(cmp.getKeyFieldCount() - 1),
+                getChildPointerOff(tupleA, cmp), childPtrSize, tupleB.getFieldData(cmp.getKeyFieldCount() - 1),
+                getChildPointerOff(tupleB, cmp), childPtrSize);
+    }
 
-	@Override
-	public int split(ITreeIndexFrame rightFrame, ITupleReference tuple,
-			MultiComparator cmp, ISplitKey splitKey) throws Exception {
+    @Override
+    public int split(ITreeIndexFrame rightFrame, ITupleReference tuple, MultiComparator cmp, ISplitKey splitKey)
+            throws Exception {
 
-		rightFrame.setPageTupleFieldCount(cmp.getKeyFieldCount());
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
+        rightFrame.setPageTupleFieldCount(cmp.getKeyFieldCount());
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
 
-		RTreeSplitKey rTreeSplitKey = ((RTreeSplitKey) splitKey);
-		RTreeTypeAwareTupleWriter rTreeTupleWriterLeftFrame = ((RTreeTypeAwareTupleWriter) tupleWriter);
-		RTreeTypeAwareTupleWriter rTreeTupleWriterRightFrame = ((RTreeTypeAwareTupleWriter) rightFrame
-				.getTupleWriter());
+        RTreeSplitKey rTreeSplitKey = ((RTreeSplitKey) splitKey);
+        RTreeTypeAwareTupleWriter rTreeTupleWriterLeftFrame = ((RTreeTypeAwareTupleWriter) tupleWriter);
+        RTreeTypeAwareTupleWriter rTreeTupleWriterRightFrame = ((RTreeTypeAwareTupleWriter) rightFrame.getTupleWriter());
 
-		// calculations are based on the R*-tree paper
-		int m = (int) Math.floor((getTupleCount() + 1) * splitFactor);
-		int splitDistribution = getTupleCount() - (2 * m) + 2;
+        // calculations are based on the R*-tree paper
+        int m = (int) Math.floor((getTupleCount() + 1) * splitFactor);
+        int splitDistribution = getTupleCount() - (2 * m) + 2;
 
-		// to calculate the minimum margin in order to pick the split axis
-		double minMargin = Double.MAX_VALUE;
-		int splitAxis = 0, sortOrder = 0;
+        // to calculate the minimum margin in order to pick the split axis
+        double minMargin = Double.MAX_VALUE;
+        int splitAxis = 0, sortOrder = 0;
 
-		int maxFieldPos = cmp.getKeyFieldCount() / 2;
-		for (int i = 0; i < maxFieldPos; i++) {
-			int j = maxFieldPos + i;
-			for (int k = 0; k < getTupleCount(); ++k) {
+        int maxFieldPos = cmp.getKeyFieldCount() / 2;
+        for (int i = 0; i < maxFieldPos; i++) {
+            int j = maxFieldPos + i;
+            for (int k = 0; k < getTupleCount(); ++k) {
 
-				frameTuple.resetByTupleIndex(this, k);
-				double LowerKey = cmp.getValueProviders()[i]
-						.getValue(frameTuple.getFieldData(i),
-								frameTuple.getFieldStart(i));
-				double UpperKey = cmp.getValueProviders()[j]
-						.getValue(frameTuple.getFieldData(j),
-								frameTuple.getFieldStart(j));
+                frameTuple.resetByTupleIndex(this, k);
+                double LowerKey = cmp.getValueProviders()[i].getValue(frameTuple.getFieldData(i),
+                        frameTuple.getFieldStart(i));
+                double UpperKey = cmp.getValueProviders()[j].getValue(frameTuple.getFieldData(j),
+                        frameTuple.getFieldStart(j));
 
-				tupleEntries1.add(k, LowerKey);
-				tupleEntries2.add(k, UpperKey);
-			}
-			double LowerKey = cmp.getValueProviders()[i].getValue(
-					tuple.getFieldData(i), tuple.getFieldStart(i));
-			double UpperKey = cmp.getValueProviders()[j].getValue(
-					tuple.getFieldData(j), tuple.getFieldStart(j));
+                tupleEntries1.add(k, LowerKey);
+                tupleEntries2.add(k, UpperKey);
+            }
+            double LowerKey = cmp.getValueProviders()[i].getValue(tuple.getFieldData(i), tuple.getFieldStart(i));
+            double UpperKey = cmp.getValueProviders()[j].getValue(tuple.getFieldData(j), tuple.getFieldStart(j));
 
-			tupleEntries1.add(-1, LowerKey);
-			tupleEntries2.add(-1, UpperKey);
+            tupleEntries1.add(-1, LowerKey);
+            tupleEntries2.add(-1, UpperKey);
 
-			tupleEntries1.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
-			tupleEntries2.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
+            tupleEntries1.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
+            tupleEntries2.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
 
-			double lowerMargin = 0.0, upperMargin = 0.0;
-			// generate distribution
-			for (int k = 1; k <= splitDistribution; ++k) {
-				int d = m - 1 + k;
+            double lowerMargin = 0.0, upperMargin = 0.0;
+            // generate distribution
+            for (int k = 1; k <= splitDistribution; ++k) {
+                int d = m - 1 + k;
 
-				generateDist(tuple, tupleEntries1, rec[0], 0, d, cmp);
-				generateDist(tuple, tupleEntries2, rec[1], 0, d, cmp);
-				generateDist(tuple, tupleEntries1, rec[2], d,
-						getTupleCount() + 1, cmp);
-				generateDist(tuple, tupleEntries2, rec[3], d,
-						getTupleCount() + 1, cmp);
+                generateDist(tuple, tupleEntries1, rec[0], 0, d, cmp);
+                generateDist(tuple, tupleEntries2, rec[1], 0, d, cmp);
+                generateDist(tuple, tupleEntries1, rec[2], d, getTupleCount() + 1, cmp);
+                generateDist(tuple, tupleEntries2, rec[3], d, getTupleCount() + 1, cmp);
 
-				// calculate the margin of the distributions
-				lowerMargin += rec[0].margin() + rec[2].margin();
-				upperMargin += rec[1].margin() + rec[3].margin();
-			}
-			double margin = Math.min(lowerMargin, upperMargin);
+                // calculate the margin of the distributions
+                lowerMargin += rec[0].margin() + rec[2].margin();
+                upperMargin += rec[1].margin() + rec[3].margin();
+            }
+            double margin = Math.min(lowerMargin, upperMargin);
 
-			// store minimum margin as split axis
-			if (margin < minMargin) {
-				minMargin = margin;
-				splitAxis = i;
-				sortOrder = (lowerMargin < upperMargin) ? 0 : 2;
-			}
+            // store minimum margin as split axis
+            if (margin < minMargin) {
+                minMargin = margin;
+                splitAxis = i;
+                sortOrder = (lowerMargin < upperMargin) ? 0 : 2;
+            }
 
-			tupleEntries1.clear();
-			tupleEntries2.clear();
-		}
+            tupleEntries1.clear();
+            tupleEntries2.clear();
+        }
 
-		for (int i = 0; i < getTupleCount(); ++i) {
-			frameTuple.resetByTupleIndex(this, i);
-			double key = cmp.getValueProviders()[splitAxis + sortOrder]
-					.getValue(frameTuple.getFieldData(splitAxis + sortOrder),
-							frameTuple.getFieldStart(splitAxis + sortOrder));
-			tupleEntries1.add(i, key);
-		}
-		double key = cmp.getValueProviders()[splitAxis + sortOrder].getValue(
-				tuple.getFieldData(splitAxis + sortOrder),
-				tuple.getFieldStart(splitAxis + sortOrder));
-		tupleEntries1.add(-1, key);
-		tupleEntries1.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
+        for (int i = 0; i < getTupleCount(); ++i) {
+            frameTuple.resetByTupleIndex(this, i);
+            double key = cmp.getValueProviders()[splitAxis + sortOrder].getValue(
+                    frameTuple.getFieldData(splitAxis + sortOrder), frameTuple.getFieldStart(splitAxis + sortOrder));
+            tupleEntries1.add(i, key);
+        }
+        double key = cmp.getValueProviders()[splitAxis + sortOrder].getValue(tuple.getFieldData(splitAxis + sortOrder),
+                tuple.getFieldStart(splitAxis + sortOrder));
+        tupleEntries1.add(-1, key);
+        tupleEntries1.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
 
-		double minArea = Double.MAX_VALUE;
-		double minOverlap = Double.MAX_VALUE;
-		int splitPoint = 0;
-		for (int i = 1; i <= splitDistribution; ++i) {
-			int d = m - 1 + i;
+        double minArea = Double.MAX_VALUE;
+        double minOverlap = Double.MAX_VALUE;
+        int splitPoint = 0;
+        for (int i = 1; i <= splitDistribution; ++i) {
+            int d = m - 1 + i;
 
-			generateDist(tuple, tupleEntries1, rec[0], 0, d, cmp);
-			generateDist(tuple, tupleEntries1, rec[2], d, getTupleCount() + 1,
-					cmp);
+            generateDist(tuple, tupleEntries1, rec[0], 0, d, cmp);
+            generateDist(tuple, tupleEntries1, rec[2], d, getTupleCount() + 1, cmp);
 
-			double overlap = rec[0].overlappedArea(rec[2]);
-			if (overlap < minOverlap) {
-				splitPoint = d;
-				minOverlap = overlap;
-				minArea = rec[0].area() + rec[2].area();
-			} else if (overlap == minOverlap) {
-				double area = rec[0].area() + rec[2].area();
-				if (area < minArea) {
-					splitPoint = d;
-					minArea = area;
-				}
-			}
-		}
-		int startIndex, endIndex;
-		if (splitPoint < (getTupleCount() + 1) / 2) {
-			startIndex = 0;
-			endIndex = splitPoint;
-		} else {
-			startIndex = splitPoint;
-			endIndex = (getTupleCount() + 1);
-		}
-		boolean tupleInserted = false;
-		int totalBytes = 0, numOfDeletedTuples = 0;
-		for (int i = startIndex; i < endIndex; i++) {
-			if (tupleEntries1.get(i).getTupleIndex() != -1) {
-				frameTuple.resetByTupleIndex(this, tupleEntries1.get(i)
-						.getTupleIndex());
-				rightFrame.insert(frameTuple, cmp, -1);
-				((UnorderedSlotManager) slotManager).modifySlot(slotManager
-						.getSlotOff(tupleEntries1.get(i).getTupleIndex()), -1);
-				totalBytes += tupleWriter.bytesRequired(frameTuple)
-						+ childPtrSize;
-				numOfDeletedTuples++;
-			} else {
-				rightFrame.insert(tuple, cmp, -1);
-				tupleInserted = true;
-			}
-		}
+            double overlap = rec[0].overlappedArea(rec[2]);
+            if (overlap < minOverlap) {
+                splitPoint = d;
+                minOverlap = overlap;
+                minArea = rec[0].area() + rec[2].area();
+            } else if (overlap == minOverlap) {
+                double area = rec[0].area() + rec[2].area();
+                if (area < minArea) {
+                    splitPoint = d;
+                    minArea = area;
+                }
+            }
+        }
+        int startIndex, endIndex;
+        if (splitPoint < (getTupleCount() + 1) / 2) {
+            startIndex = 0;
+            endIndex = splitPoint;
+        } else {
+            startIndex = splitPoint;
+            endIndex = (getTupleCount() + 1);
+        }
+        boolean tupleInserted = false;
+        int totalBytes = 0, numOfDeletedTuples = 0;
+        for (int i = startIndex; i < endIndex; i++) {
+            if (tupleEntries1.get(i).getTupleIndex() != -1) {
+                frameTuple.resetByTupleIndex(this, tupleEntries1.get(i).getTupleIndex());
+                rightFrame.insert(frameTuple, cmp, -1);
+                ((UnorderedSlotManager) slotManager).modifySlot(
+                        slotManager.getSlotOff(tupleEntries1.get(i).getTupleIndex()), -1);
+                totalBytes += tupleWriter.bytesRequired(frameTuple) + childPtrSize;
+                numOfDeletedTuples++;
+            } else {
+                rightFrame.insert(tuple, cmp, -1);
+                tupleInserted = true;
+            }
+        }
 
-		((UnorderedSlotManager) slotManager).deleteEmptySlots();
+        ((UnorderedSlotManager) slotManager).deleteEmptySlots();
 
-		// maintain space information
-		buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff)
-				+ totalBytes + (slotManager.getSlotSize() * numOfDeletedTuples));
+        // maintain space information
+        buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) + totalBytes
+                + (slotManager.getSlotSize() * numOfDeletedTuples));
 
-		// compact both pages
-		rightFrame.compact(cmp);
-		compact(cmp);
+        // compact both pages
+        rightFrame.compact(cmp);
+        compact(cmp);
 
-		if (!tupleInserted) {
-			insert(tuple, cmp, -1);
-		}
+        if (!tupleInserted) {
+            insert(tuple, cmp, -1);
+        }
 
-		int tupleOff = slotManager.getTupleOff(slotManager.getSlotEndOff());
-		frameTuple.resetByTupleOffset(buf, tupleOff);
-		int splitKeySize = tupleWriter.bytesRequired(frameTuple, 0,
-				cmp.getKeyFieldCount());
+        int tupleOff = slotManager.getTupleOff(slotManager.getSlotEndOff());
+        frameTuple.resetByTupleOffset(buf, tupleOff);
+        int splitKeySize = tupleWriter.bytesRequired(frameTuple, 0, cmp.getKeyFieldCount());
 
-		splitKey.initData(splitKeySize);
-		this.adjustMBR(tuples, cmp);
-		rTreeTupleWriterLeftFrame.writeTupleFields(tuples, 0,
-				rTreeSplitKey.getLeftPageBuffer(), 0);
-		rTreeSplitKey.getLeftTuple().resetByTupleOffset(
-				rTreeSplitKey.getLeftPageBuffer(), 0);
+        splitKey.initData(splitKeySize);
+        this.adjustMBR(tuples, cmp);
+        rTreeTupleWriterLeftFrame.writeTupleFields(tuples, 0, rTreeSplitKey.getLeftPageBuffer(), 0);
+        rTreeSplitKey.getLeftTuple().resetByTupleOffset(rTreeSplitKey.getLeftPageBuffer(), 0);
 
-		((IRTreeFrame) rightFrame).adjustMBR(
-				((RTreeNSMFrame) rightFrame).getTuples(), cmp);
-		rTreeTupleWriterRightFrame.writeTupleFields(
-				((RTreeNSMFrame) rightFrame).getTuples(), 0,
-				rTreeSplitKey.getRightPageBuffer(), 0);
-		rTreeSplitKey.getRightTuple().resetByTupleOffset(
-				rTreeSplitKey.getRightPageBuffer(), 0);
+        ((IRTreeFrame) rightFrame).adjustMBR(((RTreeNSMFrame) rightFrame).getTuples(), cmp);
+        rTreeTupleWriterRightFrame.writeTupleFields(((RTreeNSMFrame) rightFrame).getTuples(), 0,
+                rTreeSplitKey.getRightPageBuffer(), 0);
+        rTreeSplitKey.getRightTuple().resetByTupleOffset(rTreeSplitKey.getRightPageBuffer(), 0);
 
-		tupleEntries1.clear();
-		tupleEntries2.clear();
-		return 0;
-	}
+        tupleEntries1.clear();
+        tupleEntries2.clear();
+        return 0;
+    }
 
-	private int getChildPointerOff(ITupleReference tuple, MultiComparator cmp) {
-		return tuple.getFieldStart(cmp.getKeyFieldCount() - 1)
-				+ tuple.getFieldLength(cmp.getKeyFieldCount() - 1);
-	}
+    private int getChildPointerOff(ITupleReference tuple, MultiComparator cmp) {
+        return tuple.getFieldStart(cmp.getKeyFieldCount() - 1) + tuple.getFieldLength(cmp.getKeyFieldCount() - 1);
+    }
 
-	@Override
-	public void insert(ITupleReference tuple, MultiComparator cmp,
-			int tupleIndex) throws Exception {
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
-		slotManager.insertSlot(-1, buf.getInt(freeSpaceOff));
-		int freeSpace = buf.getInt(freeSpaceOff);
-		int bytesWritten = tupleWriter.writeTupleFields(tuple, 0,
-				cmp.getKeyFieldCount(), buf, freeSpace);
-		System.arraycopy(tuple.getFieldData(cmp.getKeyFieldCount() - 1),
-				getChildPointerOff(tuple, cmp), buf.array(), freeSpace
-						+ bytesWritten, childPtrSize);
-		int tupleSize = bytesWritten + childPtrSize;
+    @Override
+    public void insert(ITupleReference tuple, MultiComparator cmp, int tupleIndex) throws Exception {
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
+        slotManager.insertSlot(-1, buf.getInt(freeSpaceOff));
+        int freeSpace = buf.getInt(freeSpaceOff);
+        int bytesWritten = tupleWriter.writeTupleFields(tuple, 0, cmp.getKeyFieldCount(), buf, freeSpace);
+        System.arraycopy(tuple.getFieldData(cmp.getKeyFieldCount() - 1), getChildPointerOff(tuple, cmp), buf.array(),
+                freeSpace + bytesWritten, childPtrSize);
+        int tupleSize = bytesWritten + childPtrSize;
 
-		buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
-		buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + tupleSize);
-		buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) - tupleSize
-				- slotManager.getSlotSize());
+        buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
+        buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + tupleSize);
+        buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) - tupleSize - slotManager.getSlotSize());
 
-	}
+    }
 
-	@Override
-	public void delete(int tupleIndex, MultiComparator cmp) throws Exception {
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
-		int slotOff = slotManager.getSlotOff(tupleIndex);
+    @Override
+    public void delete(int tupleIndex, MultiComparator cmp) throws Exception {
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
+        int slotOff = slotManager.getSlotOff(tupleIndex);
 
-		int tupleOff = slotManager.getTupleOff(slotOff);
-		frameTuple.resetByTupleOffset(buf, tupleOff);
-		int tupleSize = tupleWriter.bytesRequired(frameTuple);
+        int tupleOff = slotManager.getTupleOff(slotOff);
+        frameTuple.resetByTupleOffset(buf, tupleOff);
+        int tupleSize = tupleWriter.bytesRequired(frameTuple);
 
-		// perform deletion (we just do a memcpy to overwrite the slot)
-		int slotStartOff = slotManager.getSlotEndOff();
-		int length = slotOff - slotStartOff;
-		System.arraycopy(buf.array(), slotStartOff, buf.array(), slotStartOff
-				+ slotManager.getSlotSize(), length);
+        // perform deletion (we just do a memcpy to overwrite the slot)
+        int slotStartOff = slotManager.getSlotEndOff();
+        int length = slotOff - slotStartOff;
+        System.arraycopy(buf.array(), slotStartOff, buf.array(), slotStartOff + slotManager.getSlotSize(), length);
 
-		// maintain space information
-		buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) - 1);
-		buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) + tupleSize
-				+ childPtrSize + slotManager.getSlotSize());
-	}
+        // maintain space information
+        buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) - 1);
+        buf.putInt(totalFreeSpaceOff,
+                buf.getInt(totalFreeSpaceOff) + tupleSize + childPtrSize + slotManager.getSlotSize());
+    }
 
-	@Override
-	public boolean recomputeMBR(ITupleReference tuple, int tupleIndex,
-			MultiComparator cmp) {
-		frameTuple.setFieldCount(cmp.getKeyFieldCount());
-		frameTuple.resetByTupleIndex(this, tupleIndex);
+    @Override
+    public boolean recomputeMBR(ITupleReference tuple, int tupleIndex, MultiComparator cmp) {
+        frameTuple.setFieldCount(cmp.getKeyFieldCount());
+        frameTuple.resetByTupleIndex(this, tupleIndex);
 
-		int maxFieldPos = cmp.getKeyFieldCount() / 2;
-		for (int i = 0; i < maxFieldPos; i++) {
-			int j = maxFieldPos + i;
-			int c = cmp.getComparators()[i].compare(frameTuple.getFieldData(i),
-					frameTuple.getFieldStart(i), frameTuple.getFieldLength(i),
-					tuple.getFieldData(i), tuple.getFieldStart(i),
-					tuple.getFieldLength(i));
-			if (c != 0) {
-				return true;
-			}
-			c = cmp.getComparators()[j].compare(frameTuple.getFieldData(j),
-					frameTuple.getFieldStart(j), frameTuple.getFieldLength(j),
-					tuple.getFieldData(j), tuple.getFieldStart(j),
-					tuple.getFieldLength(j));
+        int maxFieldPos = cmp.getKeyFieldCount() / 2;
+        for (int i = 0; i < maxFieldPos; i++) {
+            int j = maxFieldPos + i;
+            int c = cmp.getComparators()[i].compare(frameTuple.getFieldData(i), frameTuple.getFieldStart(i),
+                    frameTuple.getFieldLength(i), tuple.getFieldData(i), tuple.getFieldStart(i),
+                    tuple.getFieldLength(i));
+            if (c != 0) {
+                return true;
+            }
+            c = cmp.getComparators()[j].compare(frameTuple.getFieldData(j), frameTuple.getFieldStart(j),
+                    frameTuple.getFieldLength(j), tuple.getFieldData(j), tuple.getFieldStart(j),
+                    tuple.getFieldLength(j));
 
-			if (c != 0) {
-				return true;
-			}
-		}
-		return false;
-	}
+            if (c != 0) {
+                return true;
+            }
+        }
+        return false;
+    }
 
-	private double overlappedArea(ITupleReference tuple1,
-			ITupleReference tupleToBeInserted, ITupleReference tuple2,
-			MultiComparator cmp) {
-		double area = 1.0;
-		double f1, f2;
+    private double overlappedArea(ITupleReference tuple1, ITupleReference tupleToBeInserted, ITupleReference tuple2,
+            MultiComparator cmp) {
+        double area = 1.0;
+        double f1, f2;
 
-		int maxFieldPos = cmp.getKeyFieldCount() / 2;
-		for (int i = 0; i < maxFieldPos; i++) {
-			int j = maxFieldPos + i;
-			double pHigh1, pLow1;
-			if (tupleToBeInserted != null) {
-				int c = cmp.getComparators()[i].compare(tuple1.getFieldData(i),
-						tuple1.getFieldStart(i), tuple1.getFieldLength(i),
-						tupleToBeInserted.getFieldData(i),
-						tupleToBeInserted.getFieldStart(i),
-						tupleToBeInserted.getFieldLength(i));
-				if (c < 0) {
-					pLow1 = cmp.getValueProviders()[i].getValue(
-							tuple1.getFieldData(i), tuple1.getFieldStart(i));
-				} else {
-					pLow1 = cmp.getValueProviders()[i].getValue(
-							tupleToBeInserted.getFieldData(i),
-							tupleToBeInserted.getFieldStart(i));
-				}
+        int maxFieldPos = cmp.getKeyFieldCount() / 2;
+        for (int i = 0; i < maxFieldPos; i++) {
+            int j = maxFieldPos + i;
+            double pHigh1, pLow1;
+            if (tupleToBeInserted != null) {
+                int c = cmp.getComparators()[i].compare(tuple1.getFieldData(i), tuple1.getFieldStart(i),
+                        tuple1.getFieldLength(i), tupleToBeInserted.getFieldData(i),
+                        tupleToBeInserted.getFieldStart(i), tupleToBeInserted.getFieldLength(i));
+                if (c < 0) {
+                    pLow1 = cmp.getValueProviders()[i].getValue(tuple1.getFieldData(i), tuple1.getFieldStart(i));
+                } else {
+                    pLow1 = cmp.getValueProviders()[i].getValue(tupleToBeInserted.getFieldData(i),
+                            tupleToBeInserted.getFieldStart(i));
+                }
 
-				c = cmp.getComparators()[j].compare(tuple1.getFieldData(j),
-						tuple1.getFieldStart(j), tuple1.getFieldLength(j),
-						tupleToBeInserted.getFieldData(j),
-						tupleToBeInserted.getFieldStart(j),
-						tupleToBeInserted.getFieldLength(j));
-				if (c > 0) {
-					pHigh1 = cmp.getValueProviders()[j].getValue(
-							tuple1.getFieldData(j), tuple1.getFieldStart(j));
-				} else {
-					pHigh1 = cmp.getValueProviders()[j].getValue(
-							tupleToBeInserted.getFieldData(j),
-							tupleToBeInserted.getFieldStart(j));
-				}
-			} else {
-				pLow1 = cmp.getValueProviders()[i].getValue(
-						tuple1.getFieldData(i), tuple1.getFieldStart(i));
-				pHigh1 = cmp.getValueProviders()[j].getValue(
-						tuple1.getFieldData(j), tuple1.getFieldStart(j));
-			}
+                c = cmp.getComparators()[j].compare(tuple1.getFieldData(j), tuple1.getFieldStart(j),
+                        tuple1.getFieldLength(j), tupleToBeInserted.getFieldData(j),
+                        tupleToBeInserted.getFieldStart(j), tupleToBeInserted.getFieldLength(j));
+                if (c > 0) {
+                    pHigh1 = cmp.getValueProviders()[j].getValue(tuple1.getFieldData(j), tuple1.getFieldStart(j));
+                } else {
+                    pHigh1 = cmp.getValueProviders()[j].getValue(tupleToBeInserted.getFieldData(j),
+                            tupleToBeInserted.getFieldStart(j));
+                }
+            } else {
+                pLow1 = cmp.getValueProviders()[i].getValue(tuple1.getFieldData(i), tuple1.getFieldStart(i));
+                pHigh1 = cmp.getValueProviders()[j].getValue(tuple1.getFieldData(j), tuple1.getFieldStart(j));
+            }
 
-			double pLow2 = cmp.getValueProviders()[i].getValue(
-					tuple2.getFieldData(i), tuple2.getFieldStart(i));
-			double pHigh2 = cmp.getValueProviders()[j].getValue(
-					tuple2.getFieldData(j), tuple2.getFieldStart(j));
+            double pLow2 = cmp.getValueProviders()[i].getValue(tuple2.getFieldData(i), tuple2.getFieldStart(i));
+            double pHigh2 = cmp.getValueProviders()[j].getValue(tuple2.getFieldData(j), tuple2.getFieldStart(j));
 
-			if (pLow1 > pHigh2 || pHigh1 < pLow2) {
-				return 0.0;
-			}
+            if (pLow1 > pHigh2 || pHigh1 < pLow2) {
+                return 0.0;
+            }
 
-			f1 = Math.max(pLow1, pLow2);
-			f2 = Math.min(pHigh1, pHigh2);
-			area *= f2 - f1;
-		}
-		return area;
-	}
+            f1 = Math.max(pLow1, pLow2);
+            f2 = Math.min(pHigh1, pHigh2);
+            area *= f2 - f1;
+        }
+        return area;
+    }
 
-	private double enlargedArea(ITupleReference tuple,
-			ITupleReference tupleToBeInserted, MultiComparator cmp) {
-		double areaBeforeEnlarge = area(tuple, cmp);
-		double areaAfterEnlarge = 1.0;
+    private double enlargedArea(ITupleReference tuple, ITupleReference tupleToBeInserted, MultiComparator cmp) {
+        double areaBeforeEnlarge = area(tuple, cmp);
+        double areaAfterEnlarge = 1.0;
 
-		int maxFieldPos = cmp.getKeyFieldCount() / 2;
-		for (int i = 0; i < maxFieldPos; i++) {
-			int j = maxFieldPos + i;
-			double pHigh, pLow;
-			int c = cmp.getComparators()[i].compare(tuple.getFieldData(i),
-					tuple.getFieldStart(i), tuple.getFieldLength(i),
-					tupleToBeInserted.getFieldData(i),
-					tupleToBeInserted.getFieldStart(i),
-					tupleToBeInserted.getFieldLength(i));
-			if (c < 0) {
-				pLow = cmp.getValueProviders()[i].getValue(
-						tuple.getFieldData(i), tuple.getFieldStart(i));
-			} else {
-				pLow = cmp.getValueProviders()[i].getValue(
-						tupleToBeInserted.getFieldData(i),
-						tupleToBeInserted.getFieldStart(i));
-			}
+        int maxFieldPos = cmp.getKeyFieldCount() / 2;
+        for (int i = 0; i < maxFieldPos; i++) {
+            int j = maxFieldPos + i;
+            double pHigh, pLow;
+            int c = cmp.getComparators()[i].compare(tuple.getFieldData(i), tuple.getFieldStart(i),
+                    tuple.getFieldLength(i), tupleToBeInserted.getFieldData(i), tupleToBeInserted.getFieldStart(i),
+                    tupleToBeInserted.getFieldLength(i));
+            if (c < 0) {
+                pLow = cmp.getValueProviders()[i].getValue(tuple.getFieldData(i), tuple.getFieldStart(i));
+            } else {
+                pLow = cmp.getValueProviders()[i].getValue(tupleToBeInserted.getFieldData(i),
+                        tupleToBeInserted.getFieldStart(i));
+            }
 
-			c = cmp.getComparators()[j].compare(tuple.getFieldData(j),
-					tuple.getFieldStart(j), tuple.getFieldLength(j),
-					tupleToBeInserted.getFieldData(j),
-					tupleToBeInserted.getFieldStart(j),
-					tupleToBeInserted.getFieldLength(j));
-			if (c > 0) {
-				pHigh = cmp.getValueProviders()[j].getValue(
-						tuple.getFieldData(j), tuple.getFieldStart(j));
-			} else {
-				pHigh = cmp.getValueProviders()[j].getValue(
-						tupleToBeInserted.getFieldData(j),
-						tupleToBeInserted.getFieldStart(j));
-			}
-			areaAfterEnlarge *= pHigh - pLow;
-		}
-		return areaAfterEnlarge - areaBeforeEnlarge;
-	}
+            c = cmp.getComparators()[j].compare(tuple.getFieldData(j), tuple.getFieldStart(j), tuple.getFieldLength(j),
+                    tupleToBeInserted.getFieldData(j), tupleToBeInserted.getFieldStart(j),
+                    tupleToBeInserted.getFieldLength(j));
+            if (c > 0) {
+                pHigh = cmp.getValueProviders()[j].getValue(tuple.getFieldData(j), tuple.getFieldStart(j));
+            } else {
+                pHigh = cmp.getValueProviders()[j].getValue(tupleToBeInserted.getFieldData(j),
+                        tupleToBeInserted.getFieldStart(j));
+            }
+            areaAfterEnlarge *= pHigh - pLow;
+        }
+        return areaAfterEnlarge - areaBeforeEnlarge;
+    }
 
-	private double area(ITupleReference tuple, MultiComparator cmp) {
-		double area = 1.0;
-		int maxFieldPos = cmp.getKeyFieldCount() / 2;
-		for (int i = 0; i < maxFieldPos; i++) {
-			int j = maxFieldPos + i;
-			area *= cmp.getValueProviders()[j].getValue(tuple.getFieldData(j),
-					tuple.getFieldStart(j))
-					- cmp.getValueProviders()[i].getValue(
-							tuple.getFieldData(i), tuple.getFieldStart(i));
-		}
-		return area;
-	}
+    private double area(ITupleReference tuple, MultiComparator cmp) {
+        double area = 1.0;
+        int maxFieldPos = cmp.getKeyFieldCount() / 2;
+        for (int i = 0; i < maxFieldPos; i++) {
+            int j = maxFieldPos + i;
+            area *= cmp.getValueProviders()[j].getValue(tuple.getFieldData(j), tuple.getFieldStart(j))
+                    - cmp.getValueProviders()[i].getValue(tuple.getFieldData(i), tuple.getFieldStart(i));
+        }
+        return area;
+    }
 
-	@Override
-	public void enlarge(ITupleReference tuple, MultiComparator cmp) {
-		int maxFieldPos = cmp.getKeyFieldCount() / 2;
-		for (int i = 0; i < maxFieldPos; i++) {
-			int j = maxFieldPos + i;
-			int c = cmp.getComparators()[i].compare(frameTuple.getFieldData(i),
-					frameTuple.getFieldStart(i), frameTuple.getFieldLength(i),
-					tuple.getFieldData(i), tuple.getFieldStart(i),
-					tuple.getFieldLength(i));
-			if (c > 0) {
-				System.arraycopy(tuple.getFieldData(i), tuple.getFieldStart(i),
-						frameTuple.getFieldData(i),
-						frameTuple.getFieldStart(i), tuple.getFieldLength(i));
-			}
-			c = cmp.getComparators()[j].compare(frameTuple.getFieldData(j),
-					frameTuple.getFieldStart(j), frameTuple.getFieldLength(j),
-					tuple.getFieldData(j), tuple.getFieldStart(j),
-					tuple.getFieldLength(j));
-			if (c < 0) {
-				System.arraycopy(tuple.getFieldData(j), tuple.getFieldStart(j),
-						frameTuple.getFieldData(j),
-						frameTuple.getFieldStart(j), tuple.getFieldLength(j));
-			}
-		}
-	}
+    @Override
+    public void enlarge(ITupleReference tuple, MultiComparator cmp) {
+        int maxFieldPos = cmp.getKeyFieldCount() / 2;
+        for (int i = 0; i < maxFieldPos; i++) {
+            int j = maxFieldPos + i;
+            int c = cmp.getComparators()[i].compare(frameTuple.getFieldData(i), frameTuple.getFieldStart(i),
+                    frameTuple.getFieldLength(i), tuple.getFieldData(i), tuple.getFieldStart(i),
+                    tuple.getFieldLength(i));
+            if (c > 0) {
+                System.arraycopy(tuple.getFieldData(i), tuple.getFieldStart(i), frameTuple.getFieldData(i),
+                        frameTuple.getFieldStart(i), tuple.getFieldLength(i));
+            }
+            c = cmp.getComparators()[j].compare(frameTuple.getFieldData(j), frameTuple.getFieldStart(j),
+                    frameTuple.getFieldLength(j), tuple.getFieldData(j), tuple.getFieldStart(j),
+                    tuple.getFieldLength(j));
+            if (c < 0) {
+                System.arraycopy(tuple.getFieldData(j), tuple.getFieldStart(j), frameTuple.getFieldData(j),
+                        frameTuple.getFieldStart(j), tuple.getFieldLength(j));
+            }
+        }
+    }
 
-	@Override
-	public void adjustMBR(ITreeIndexTupleReference[] tuples, MultiComparator cmp) {
-		for (int i = 0; i < tuples.length; i++) {
-			tuples[i].setFieldCount(cmp.getKeyFieldCount());
-			tuples[i].resetByTupleIndex(this, 0);
-		}
+    @Override
+    public void adjustMBR(ITreeIndexTupleReference[] tuples, MultiComparator cmp) {
+        for (int i = 0; i < tuples.length; i++) {
+            tuples[i].setFieldCount(cmp.getKeyFieldCount());
+            tuples[i].resetByTupleIndex(this, 0);
+        }
 
-		adjustMBRImpl(tuples, cmp);
-	}
-}
\ No newline at end of file
+        adjustMBRImpl(tuples, cmp);
+    }
+}
diff --git a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMInteriorFrameFactory.java b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMInteriorFrameFactory.java
index 100b4d8..227d351 100644
--- a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMInteriorFrameFactory.java
+++ b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMInteriorFrameFactory.java
@@ -21,23 +21,25 @@
 
 public class RTreeNSMInteriorFrameFactory implements ITreeIndexFrameFactory {
 
-	private static final long serialVersionUID = 1L;
-	private ITreeIndexTupleWriterFactory tupleWriterFactory;
-	private int keyFieldCount;
+    private static final long serialVersionUID = 1L;
+    private final ITreeIndexTupleWriterFactory tupleWriterFactory;
+    private final int keyFieldCount;
 
-	public RTreeNSMInteriorFrameFactory(
-			ITreeIndexTupleWriterFactory tupleWriterFactory, int keyFieldCount) {
-		this.tupleWriterFactory = tupleWriterFactory;
-		if (keyFieldCount % 2 != 0) {
-			throw new IllegalArgumentException(
-					"The key has different number of dimensions.");
-		}
-		this.keyFieldCount = keyFieldCount;
-	}
+    public RTreeNSMInteriorFrameFactory(ITreeIndexTupleWriterFactory tupleWriterFactory, int keyFieldCount) {
+        this.tupleWriterFactory = tupleWriterFactory;
+        if (keyFieldCount % 2 != 0) {
+            throw new IllegalArgumentException("The key has different number of dimensions.");
+        }
+        this.keyFieldCount = keyFieldCount;
+    }
+
+    @Override
+    public IRTreeInteriorFrame createFrame() {
+        return new RTreeNSMInteriorFrame(tupleWriterFactory.createTupleWriter(), keyFieldCount);
+    }
 
 	@Override
-	public IRTreeInteriorFrame createFrame() {
-		return new RTreeNSMInteriorFrame(
-				tupleWriterFactory.createTupleWriter(), keyFieldCount);
+	public ITreeIndexTupleWriterFactory getTupleWriterFactory() {
+		return tupleWriterFactory;
 	}
-}
\ No newline at end of file
+}
diff --git a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMLeafFrame.java b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMLeafFrame.java
index fa2ad32..ed366ca 100644
--- a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMLeafFrame.java
+++ b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMLeafFrame.java
@@ -30,263 +30,236 @@
 
 public class RTreeNSMLeafFrame extends RTreeNSMFrame implements IRTreeLeafFrame {
 
-	public RTreeNSMLeafFrame(ITreeIndexTupleWriter tupleWriter,
-			int keyFieldCount) {
-		super(tupleWriter, keyFieldCount);
-	}
+    public RTreeNSMLeafFrame(ITreeIndexTupleWriter tupleWriter, int keyFieldCount) {
+        super(tupleWriter, keyFieldCount);
+    }
 
-	@Override
-	public int findTupleIndex(ITupleReference tuple, MultiComparator cmp) {
-		frameTuple.setFieldCount(cmp.getFieldCount());
-		return slotManager.findTupleIndex(tuple, frameTuple, cmp, null, null);
-	}
+    @Override
+    public int findTupleIndex(ITupleReference tuple, MultiComparator cmp) {
+        frameTuple.setFieldCount(cmp.getFieldCount());
+        return slotManager.findTupleIndex(tuple, frameTuple, cmp, null, null);
+    }
 
-	@Override
-	public boolean intersect(ITupleReference tuple, int tupleIndex,
-			MultiComparator cmp) {
-		frameTuple.setFieldCount(cmp.getFieldCount());
-		frameTuple.resetByTupleIndex(this, tupleIndex);
-		int maxFieldPos = cmp.getKeyFieldCount() / 2;
-		for (int i = 0; i < maxFieldPos; i++) {
-			int j = maxFieldPos + i;
-			int c = cmp.getComparators()[i].compare(tuple.getFieldData(i),
-					tuple.getFieldStart(i), tuple.getFieldLength(i),
-					frameTuple.getFieldData(j), frameTuple.getFieldStart(j),
-					frameTuple.getFieldLength(j));
-			if (c > 0) {
-				return false;
-			}
-			c = cmp.getComparators()[i].compare(tuple.getFieldData(j),
-					tuple.getFieldStart(j), tuple.getFieldLength(j),
-					frameTuple.getFieldData(i), frameTuple.getFieldStart(i),
-					frameTuple.getFieldLength(i));
+    @Override
+    public boolean intersect(ITupleReference tuple, int tupleIndex, MultiComparator cmp) {
+        frameTuple.setFieldCount(cmp.getFieldCount());
+        frameTuple.resetByTupleIndex(this, tupleIndex);
+        int maxFieldPos = cmp.getKeyFieldCount() / 2;
+        for (int i = 0; i < maxFieldPos; i++) {
+            int j = maxFieldPos + i;
+            int c = cmp.getComparators()[i].compare(tuple.getFieldData(i), tuple.getFieldStart(i),
+                    tuple.getFieldLength(i), frameTuple.getFieldData(j), frameTuple.getFieldStart(j),
+                    frameTuple.getFieldLength(j));
+            if (c > 0) {
+                return false;
+            }
+            c = cmp.getComparators()[i].compare(tuple.getFieldData(j), tuple.getFieldStart(j), tuple.getFieldLength(j),
+                    frameTuple.getFieldData(i), frameTuple.getFieldStart(i), frameTuple.getFieldLength(i));
 
-			if (c < 0) {
-				return false;
-			}
-		}
-		return true;
-	}
+            if (c < 0) {
+                return false;
+            }
+        }
+        return true;
+    }
 
-	@Override
-	public int split(ITreeIndexFrame rightFrame, ITupleReference tuple,
-			MultiComparator cmp, ISplitKey splitKey) throws Exception {
+    @Override
+    public int split(ITreeIndexFrame rightFrame, ITupleReference tuple, MultiComparator cmp, ISplitKey splitKey)
+            throws Exception {
 
-		rightFrame.setPageTupleFieldCount(cmp.getFieldCount());
-		frameTuple.setFieldCount(cmp.getFieldCount());
+        rightFrame.setPageTupleFieldCount(cmp.getFieldCount());
+        frameTuple.setFieldCount(cmp.getFieldCount());
 
-		RTreeSplitKey rTreeSplitKey = ((RTreeSplitKey) splitKey);
-		RTreeTypeAwareTupleWriter rTreeTupleWriterLeftFrame = ((RTreeTypeAwareTupleWriter) tupleWriter);
-		RTreeTypeAwareTupleWriter rTreeTupleWriterRightFrame = ((RTreeTypeAwareTupleWriter) rightFrame
-				.getTupleWriter());
+        RTreeSplitKey rTreeSplitKey = ((RTreeSplitKey) splitKey);
+        RTreeTypeAwareTupleWriter rTreeTupleWriterLeftFrame = ((RTreeTypeAwareTupleWriter) tupleWriter);
+        RTreeTypeAwareTupleWriter rTreeTupleWriterRightFrame = ((RTreeTypeAwareTupleWriter) rightFrame.getTupleWriter());
 
-		// calculations are based on the R*-tree paper
-		int m = (int) Math.floor((getTupleCount() + 1) * splitFactor);
-		int splitDistribution = getTupleCount() - (2 * m) + 2;
+        // calculations are based on the R*-tree paper
+        int m = (int) Math.floor((getTupleCount() + 1) * splitFactor);
+        int splitDistribution = getTupleCount() - (2 * m) + 2;
 
-		// to calculate the minimum margin in order to pick the split axis
-		double minMargin = Double.MAX_VALUE;
-		int splitAxis = 0, sortOrder = 0;
+        // to calculate the minimum margin in order to pick the split axis
+        double minMargin = Double.MAX_VALUE;
+        int splitAxis = 0, sortOrder = 0;
 
-		int maxFieldPos = cmp.getKeyFieldCount() / 2;
-		for (int i = 0; i < maxFieldPos; i++) {
-			int j = maxFieldPos + i;
-			for (int k = 0; k < getTupleCount(); ++k) {
+        int maxFieldPos = cmp.getKeyFieldCount() / 2;
+        for (int i = 0; i < maxFieldPos; i++) {
+            int j = maxFieldPos + i;
+            for (int k = 0; k < getTupleCount(); ++k) {
 
-				frameTuple.resetByTupleIndex(this, k);
+                frameTuple.resetByTupleIndex(this, k);
 
-				double LowerKey = cmp.getValueProviders()[i]
-						.getValue(frameTuple.getFieldData(i),
-								frameTuple.getFieldStart(i));
-				double UpperKey = cmp.getValueProviders()[j]
-						.getValue(frameTuple.getFieldData(j),
-								frameTuple.getFieldStart(j));
+                double LowerKey = cmp.getValueProviders()[i].getValue(frameTuple.getFieldData(i),
+                        frameTuple.getFieldStart(i));
+                double UpperKey = cmp.getValueProviders()[j].getValue(frameTuple.getFieldData(j),
+                        frameTuple.getFieldStart(j));
 
-				tupleEntries1.add(k, LowerKey);
-				tupleEntries2.add(k, UpperKey);
-			}
-			double LowerKey = cmp.getValueProviders()[i].getValue(
-					tuple.getFieldData(i), tuple.getFieldStart(i));
-			double UpperKey = cmp.getValueProviders()[j].getValue(
-					tuple.getFieldData(j), tuple.getFieldStart(j));
+                tupleEntries1.add(k, LowerKey);
+                tupleEntries2.add(k, UpperKey);
+            }
+            double LowerKey = cmp.getValueProviders()[i].getValue(tuple.getFieldData(i), tuple.getFieldStart(i));
+            double UpperKey = cmp.getValueProviders()[j].getValue(tuple.getFieldData(j), tuple.getFieldStart(j));
 
-			tupleEntries1.add(-1, LowerKey);
-			tupleEntries2.add(-1, UpperKey);
+            tupleEntries1.add(-1, LowerKey);
+            tupleEntries2.add(-1, UpperKey);
 
-			tupleEntries1.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
-			tupleEntries2.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
+            tupleEntries1.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
+            tupleEntries2.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
 
-			double lowerMargin = 0.0, upperMargin = 0.0;
-			// generate distribution
-			for (int k = 1; k <= splitDistribution; ++k) {
-				int d = m - 1 + k;
+            double lowerMargin = 0.0, upperMargin = 0.0;
+            // generate distribution
+            for (int k = 1; k <= splitDistribution; ++k) {
+                int d = m - 1 + k;
 
-				generateDist(tuple, tupleEntries1, rec[0], 0, d, cmp);
-				generateDist(tuple, tupleEntries2, rec[1], 0, d, cmp);
-				generateDist(tuple, tupleEntries1, rec[2], d,
-						getTupleCount() + 1, cmp);
-				generateDist(tuple, tupleEntries2, rec[3], d,
-						getTupleCount() + 1, cmp);
+                generateDist(tuple, tupleEntries1, rec[0], 0, d, cmp);
+                generateDist(tuple, tupleEntries2, rec[1], 0, d, cmp);
+                generateDist(tuple, tupleEntries1, rec[2], d, getTupleCount() + 1, cmp);
+                generateDist(tuple, tupleEntries2, rec[3], d, getTupleCount() + 1, cmp);
 
-				// calculate the margin of the distributions
-				lowerMargin += rec[0].margin() + rec[2].margin();
-				upperMargin += rec[1].margin() + rec[3].margin();
-			}
-			double margin = Math.min(lowerMargin, upperMargin);
+                // calculate the margin of the distributions
+                lowerMargin += rec[0].margin() + rec[2].margin();
+                upperMargin += rec[1].margin() + rec[3].margin();
+            }
+            double margin = Math.min(lowerMargin, upperMargin);
 
-			// store minimum margin as split axis
-			if (margin < minMargin) {
-				minMargin = margin;
-				splitAxis = i;
-				sortOrder = (lowerMargin < upperMargin) ? 0 : 2;
-			}
+            // store minimum margin as split axis
+            if (margin < minMargin) {
+                minMargin = margin;
+                splitAxis = i;
+                sortOrder = (lowerMargin < upperMargin) ? 0 : 2;
+            }
 
-			tupleEntries1.clear();
-			tupleEntries2.clear();
-		}
+            tupleEntries1.clear();
+            tupleEntries2.clear();
+        }
 
-		for (int i = 0; i < getTupleCount(); ++i) {
-			frameTuple.resetByTupleIndex(this, i);
-			double key = cmp.getValueProviders()[splitAxis + sortOrder]
-					.getValue(frameTuple.getFieldData(splitAxis + sortOrder),
-							frameTuple.getFieldStart(splitAxis + sortOrder));
-			tupleEntries1.add(i, key);
-		}
-		double key = cmp.getValueProviders()[splitAxis + sortOrder].getValue(
-				tuple.getFieldData(splitAxis + sortOrder),
-				tuple.getFieldStart(splitAxis + sortOrder));
-		tupleEntries1.add(-1, key);
-		tupleEntries1.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
+        for (int i = 0; i < getTupleCount(); ++i) {
+            frameTuple.resetByTupleIndex(this, i);
+            double key = cmp.getValueProviders()[splitAxis + sortOrder].getValue(
+                    frameTuple.getFieldData(splitAxis + sortOrder), frameTuple.getFieldStart(splitAxis + sortOrder));
+            tupleEntries1.add(i, key);
+        }
+        double key = cmp.getValueProviders()[splitAxis + sortOrder].getValue(tuple.getFieldData(splitAxis + sortOrder),
+                tuple.getFieldStart(splitAxis + sortOrder));
+        tupleEntries1.add(-1, key);
+        tupleEntries1.sort(EntriesOrder.ASCENDING, getTupleCount() + 1);
 
-		double minArea = Double.MAX_VALUE;
-		double minOverlap = Double.MAX_VALUE;
-		int splitPoint = 0;
-		for (int i = 1; i <= splitDistribution; ++i) {
-			int d = m - 1 + i;
+        double minArea = Double.MAX_VALUE;
+        double minOverlap = Double.MAX_VALUE;
+        int splitPoint = 0;
+        for (int i = 1; i <= splitDistribution; ++i) {
+            int d = m - 1 + i;
 
-			generateDist(tuple, tupleEntries1, rec[0], 0, d, cmp);
-			generateDist(tuple, tupleEntries1, rec[2], d, getTupleCount() + 1,
-					cmp);
+            generateDist(tuple, tupleEntries1, rec[0], 0, d, cmp);
+            generateDist(tuple, tupleEntries1, rec[2], d, getTupleCount() + 1, cmp);
 
-			double overlap = rec[0].overlappedArea(rec[2]);
-			if (overlap < minOverlap) {
-				splitPoint = d;
-				minOverlap = overlap;
-				minArea = rec[0].area() + rec[2].area();
-			} else if (overlap == minOverlap) {
-				double area = rec[0].area() + rec[2].area();
-				if (area < minArea) {
-					splitPoint = d;
-					minArea = area;
-				}
-			}
-		}
-		int startIndex, endIndex;
-		if (splitPoint < (getTupleCount() + 1) / 2) {
-			startIndex = 0;
-			endIndex = splitPoint;
-		} else {
-			startIndex = splitPoint;
-			endIndex = (getTupleCount() + 1);
-		}
-		boolean tupleInserted = false;
-		int totalBytes = 0, numOfDeletedTuples = 0;
-		for (int i = startIndex; i < endIndex; i++) {
-			if (tupleEntries1.get(i).getTupleIndex() != -1) {
-				frameTuple.resetByTupleIndex(this, tupleEntries1.get(i)
-						.getTupleIndex());
-				rightFrame.insert(frameTuple, cmp, -1);
-				((UnorderedSlotManager) slotManager).modifySlot(slotManager
-						.getSlotOff(tupleEntries1.get(i).getTupleIndex()), -1);
-				totalBytes += tupleWriter.bytesRequired(frameTuple);
-				numOfDeletedTuples++;
-			} else {
-				rightFrame.insert(tuple, cmp, -1);
-				tupleInserted = true;
-			}
-		}
+            double overlap = rec[0].overlappedArea(rec[2]);
+            if (overlap < minOverlap) {
+                splitPoint = d;
+                minOverlap = overlap;
+                minArea = rec[0].area() + rec[2].area();
+            } else if (overlap == minOverlap) {
+                double area = rec[0].area() + rec[2].area();
+                if (area < minArea) {
+                    splitPoint = d;
+                    minArea = area;
+                }
+            }
+        }
+        int startIndex, endIndex;
+        if (splitPoint < (getTupleCount() + 1) / 2) {
+            startIndex = 0;
+            endIndex = splitPoint;
+        } else {
+            startIndex = splitPoint;
+            endIndex = (getTupleCount() + 1);
+        }
+        boolean tupleInserted = false;
+        int totalBytes = 0, numOfDeletedTuples = 0;
+        for (int i = startIndex; i < endIndex; i++) {
+            if (tupleEntries1.get(i).getTupleIndex() != -1) {
+                frameTuple.resetByTupleIndex(this, tupleEntries1.get(i).getTupleIndex());
+                rightFrame.insert(frameTuple, cmp, -1);
+                ((UnorderedSlotManager) slotManager).modifySlot(
+                        slotManager.getSlotOff(tupleEntries1.get(i).getTupleIndex()), -1);
+                totalBytes += tupleWriter.bytesRequired(frameTuple);
+                numOfDeletedTuples++;
+            } else {
+                rightFrame.insert(tuple, cmp, -1);
+                tupleInserted = true;
+            }
+        }
 
-		((UnorderedSlotManager) slotManager).deleteEmptySlots();
+        ((UnorderedSlotManager) slotManager).deleteEmptySlots();
 
-		// maintain space information
-		buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff)
-				+ totalBytes + (slotManager.getSlotSize() * numOfDeletedTuples));
+        // maintain space information
+        buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) + totalBytes
+                + (slotManager.getSlotSize() * numOfDeletedTuples));
 
-		// compact both pages
-		rightFrame.compact(cmp);
-		compact(cmp);
+        // compact both pages
+        rightFrame.compact(cmp);
+        compact(cmp);
 
-		if (!tupleInserted) {
-			insert(tuple, cmp, -1);
-		}
+        if (!tupleInserted) {
+            insert(tuple, cmp, -1);
+        }
 
-		int tupleOff = slotManager.getTupleOff(slotManager.getSlotEndOff());
-		frameTuple.resetByTupleOffset(buf, tupleOff);
-		int splitKeySize = tupleWriter.bytesRequired(frameTuple, 0,
-				cmp.getKeyFieldCount());
+        int tupleOff = slotManager.getTupleOff(slotManager.getSlotEndOff());
+        frameTuple.resetByTupleOffset(buf, tupleOff);
+        int splitKeySize = tupleWriter.bytesRequired(frameTuple, 0, cmp.getKeyFieldCount());
 
-		splitKey.initData(splitKeySize);
-		this.adjustMBR(tuples, cmp);
-		rTreeTupleWriterLeftFrame.writeTupleFields(tuples, 0,
-				rTreeSplitKey.getLeftPageBuffer(), 0);
-		rTreeSplitKey.getLeftTuple().resetByTupleOffset(
-				rTreeSplitKey.getLeftPageBuffer(), 0);
+        splitKey.initData(splitKeySize);
+        this.adjustMBR(tuples, cmp);
+        rTreeTupleWriterLeftFrame.writeTupleFields(tuples, 0, rTreeSplitKey.getLeftPageBuffer(), 0);
+        rTreeSplitKey.getLeftTuple().resetByTupleOffset(rTreeSplitKey.getLeftPageBuffer(), 0);
 
-		((IRTreeFrame) rightFrame).adjustMBR(
-				((RTreeNSMFrame) rightFrame).getTuples(), cmp);
-		rTreeTupleWriterRightFrame.writeTupleFields(
-				((RTreeNSMFrame) rightFrame).getTuples(), 0,
-				rTreeSplitKey.getRightPageBuffer(), 0);
-		rTreeSplitKey.getRightTuple().resetByTupleOffset(
-				rTreeSplitKey.getRightPageBuffer(), 0);
+        ((IRTreeFrame) rightFrame).adjustMBR(((RTreeNSMFrame) rightFrame).getTuples(), cmp);
+        rTreeTupleWriterRightFrame.writeTupleFields(((RTreeNSMFrame) rightFrame).getTuples(), 0,
+                rTreeSplitKey.getRightPageBuffer(), 0);
+        rTreeSplitKey.getRightTuple().resetByTupleOffset(rTreeSplitKey.getRightPageBuffer(), 0);
 
-		tupleEntries1.clear();
-		tupleEntries2.clear();
-		return 0;
-	}
+        tupleEntries1.clear();
+        tupleEntries2.clear();
+        return 0;
+    }
 
-	@Override
-	public void insert(ITupleReference tuple, MultiComparator cmp,
-			int tupleIndex) throws Exception {
-		frameTuple.setFieldCount(cmp.getFieldCount());
-		slotManager.insertSlot(-1, buf.getInt(freeSpaceOff));
-		int bytesWritten = tupleWriter.writeTuple(tuple, buf,
-				buf.getInt(freeSpaceOff));
+    @Override
+    public void insert(ITupleReference tuple, MultiComparator cmp, int tupleIndex) throws Exception {
+        frameTuple.setFieldCount(cmp.getFieldCount());
+        slotManager.insertSlot(-1, buf.getInt(freeSpaceOff));
+        int bytesWritten = tupleWriter.writeTuple(tuple, buf.array(), buf.getInt(freeSpaceOff));
 
-		buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
-		buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + bytesWritten);
-		buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff)
-				- bytesWritten - slotManager.getSlotSize());
-	}
+        buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) + 1);
+        buf.putInt(freeSpaceOff, buf.getInt(freeSpaceOff) + bytesWritten);
+        buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) - bytesWritten - slotManager.getSlotSize());
+    }
 
-	@Override
-	public void delete(int tupleIndex, MultiComparator cmp) throws Exception {
-		frameTuple.setFieldCount(cmp.getFieldCount());
-		int slotOff = slotManager.getSlotOff(tupleIndex);
+    @Override
+    public void delete(int tupleIndex, MultiComparator cmp) throws Exception {
+        frameTuple.setFieldCount(cmp.getFieldCount());
+        int slotOff = slotManager.getSlotOff(tupleIndex);
 
-		int tupleOff = slotManager.getTupleOff(slotOff);
-		frameTuple.resetByTupleOffset(buf, tupleOff);
-		int tupleSize = tupleWriter.bytesRequired(frameTuple);
+        int tupleOff = slotManager.getTupleOff(slotOff);
+        frameTuple.resetByTupleOffset(buf, tupleOff);
+        int tupleSize = tupleWriter.bytesRequired(frameTuple);
 
-		// perform deletion (we just do a memcpy to overwrite the slot)
-		int slotStartOff = slotManager.getSlotEndOff();
-		int length = slotOff - slotStartOff;
-		System.arraycopy(buf.array(), slotStartOff, buf.array(), slotStartOff
-				+ slotManager.getSlotSize(), length);
+        // perform deletion (we just do a memcpy to overwrite the slot)
+        int slotStartOff = slotManager.getSlotEndOff();
+        int length = slotOff - slotStartOff;
+        System.arraycopy(buf.array(), slotStartOff, buf.array(), slotStartOff + slotManager.getSlotSize(), length);
 
-		// maintain space information
-		buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) - 1);
-		buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) + tupleSize
-				+ slotManager.getSlotSize());
-	}
+        // maintain space information
+        buf.putInt(tupleCountOff, buf.getInt(tupleCountOff) - 1);
+        buf.putInt(totalFreeSpaceOff, buf.getInt(totalFreeSpaceOff) + tupleSize + slotManager.getSlotSize());
+    }
 
-	@Override
-	public void adjustMBR(ITreeIndexTupleReference[] tuples, MultiComparator cmp) {
-		for (int i = 0; i < tuples.length; i++) {
-			tuples[i].setFieldCount(cmp.getFieldCount());
-			tuples[i].resetByTupleIndex(this, 0);
-		}
+    @Override
+    public void adjustMBR(ITreeIndexTupleReference[] tuples, MultiComparator cmp) {
+        for (int i = 0; i < tuples.length; i++) {
+            tuples[i].setFieldCount(cmp.getFieldCount());
+            tuples[i].resetByTupleIndex(this, 0);
+        }
 
-		adjustMBRImpl(tuples, cmp);
-	}
-}
\ No newline at end of file
+        adjustMBRImpl(tuples, cmp);
+    }
+}
diff --git a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMLeafFrameFactory.java b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMLeafFrameFactory.java
index 51a047e..d12c0b1 100644
--- a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMLeafFrameFactory.java
+++ b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/frames/RTreeNSMLeafFrameFactory.java
@@ -21,23 +21,25 @@
 
 public class RTreeNSMLeafFrameFactory implements ITreeIndexFrameFactory {
 
-	private static final long serialVersionUID = 1L;
-	private ITreeIndexTupleWriterFactory tupleWriterFactory;
-	private int keyFieldCount;
+    private static final long serialVersionUID = 1L;
+    private final ITreeIndexTupleWriterFactory tupleWriterFactory;
+    private final int keyFieldCount;
 
-	public RTreeNSMLeafFrameFactory(
-			ITreeIndexTupleWriterFactory tupleWriterFactory, int keyFieldCount) {
-		this.tupleWriterFactory = tupleWriterFactory;
-		if (keyFieldCount % 2 != 0) {
-			throw new IllegalArgumentException(
-					"The key has different number of dimensions.");
-		}
-		this.keyFieldCount = keyFieldCount;
-	}
+    public RTreeNSMLeafFrameFactory(ITreeIndexTupleWriterFactory tupleWriterFactory, int keyFieldCount) {
+        this.tupleWriterFactory = tupleWriterFactory;
+        if (keyFieldCount % 2 != 0) {
+            throw new IllegalArgumentException("The key has different number of dimensions.");
+        }
+        this.keyFieldCount = keyFieldCount;
+    }
+
+    @Override
+    public IRTreeLeafFrame createFrame() {
+        return new RTreeNSMLeafFrame(tupleWriterFactory.createTupleWriter(), keyFieldCount);
+    }
 
 	@Override
-	public IRTreeLeafFrame createFrame() {
-		return new RTreeNSMLeafFrame(tupleWriterFactory.createTupleWriter(),
-				keyFieldCount);
+	public ITreeIndexTupleWriterFactory getTupleWriterFactory() {
+		return tupleWriterFactory;
 	}
-}
\ No newline at end of file
+}
diff --git a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTree.java b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTree.java
index 03b2062..97eefe0 100644
--- a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTree.java
+++ b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTree.java
@@ -47,972 +47,901 @@
 
 public class RTree implements ITreeIndex {
 
-	private boolean created = false;
-	private boolean loaded = false;
-	private final int rootPage = 1; // the root page never changes
+    private boolean created = false;
+    private boolean loaded = false;
+    private final int rootPage = 1; // the root page never changes
 
-	private final AtomicInteger globalNsn; // Global node sequence number
-	private int numOfPages = 1;
-	private final ReadWriteLock treeLatch;
+    private final AtomicInteger globalNsn; // Global node sequence number
+    private int numOfPages = 1;
+    private final ReadWriteLock treeLatch;
 
-	private final IFreePageManager freePageManager;
-	private final IBufferCache bufferCache;
-	private int fileId;
+    private final IFreePageManager freePageManager;
+    private final IBufferCache bufferCache;
+    private int fileId;
 
-	private final SearchPredicate diskOrderScanPredicate;
-	private final ITreeIndexFrameFactory interiorFrameFactory;
-	private final ITreeIndexFrameFactory leafFrameFactory;
-	private final MultiComparator cmp;
+    private final SearchPredicate diskOrderScanPredicate;
+    private final ITreeIndexFrameFactory interiorFrameFactory;
+    private final ITreeIndexFrameFactory leafFrameFactory;
+    private final MultiComparator cmp;
 
-	public int rootSplits = 0;
-	public int[] splitsByLevel = new int[500];
-	public AtomicLong readLatchesAcquired = new AtomicLong();
-	public AtomicLong readLatchesReleased = new AtomicLong();
-	public AtomicLong writeLatchesAcquired = new AtomicLong();
-	public AtomicLong writeLatchesReleased = new AtomicLong();
-	public AtomicLong pins = new AtomicLong();
-	public AtomicLong unpins = new AtomicLong();
-	public byte currentLevel = 0;
+    public int rootSplits = 0;
+    public int[] splitsByLevel = new int[500];
+    public AtomicLong readLatchesAcquired = new AtomicLong();
+    public AtomicLong readLatchesReleased = new AtomicLong();
+    public AtomicLong writeLatchesAcquired = new AtomicLong();
+    public AtomicLong writeLatchesReleased = new AtomicLong();
+    public AtomicLong pins = new AtomicLong();
+    public AtomicLong unpins = new AtomicLong();
+    public byte currentLevel = 0;
 
-	public RTree(IBufferCache bufferCache, IFreePageManager freePageManager,
-			ITreeIndexFrameFactory interiorFrameFactory,
-			ITreeIndexFrameFactory leafFrameFactory, MultiComparator cmp) {
-		this.bufferCache = bufferCache;
-		this.freePageManager = freePageManager;
-		this.interiorFrameFactory = interiorFrameFactory;
-		this.leafFrameFactory = leafFrameFactory;
-		this.cmp = cmp;
-		globalNsn = new AtomicInteger();
-		this.treeLatch = new ReentrantReadWriteLock(true);
-		this.diskOrderScanPredicate = new SearchPredicate(null, cmp);
-	}
+    public RTree(IBufferCache bufferCache, IFreePageManager freePageManager,
+            ITreeIndexFrameFactory interiorFrameFactory, ITreeIndexFrameFactory leafFrameFactory, MultiComparator cmp) {
+        this.bufferCache = bufferCache;
+        this.freePageManager = freePageManager;
+        this.interiorFrameFactory = interiorFrameFactory;
+        this.leafFrameFactory = leafFrameFactory;
+        this.cmp = cmp;
+        globalNsn = new AtomicInteger();
+        this.treeLatch = new ReentrantReadWriteLock(true);
+        this.diskOrderScanPredicate = new SearchPredicate(null, cmp);
+    }
 
-	public void incrementGlobalNsn() {
-		globalNsn.incrementAndGet();
-	}
+    public void incrementGlobalNsn() {
+        globalNsn.incrementAndGet();
+    }
 
-	public int getGlobalNsn() {
-		return globalNsn.get();
-	}
+    public int getGlobalNsn() {
+        return globalNsn.get();
+    }
 
-	public void incrementReadLatchesAcquired() {
-		readLatchesAcquired.incrementAndGet();
-	}
+    public void incrementReadLatchesAcquired() {
+        readLatchesAcquired.incrementAndGet();
+    }
 
-	public void incrementReadLatchesReleased() {
-		readLatchesReleased.incrementAndGet();
-	}
+    public void incrementReadLatchesReleased() {
+        readLatchesReleased.incrementAndGet();
+    }
 
-	public void incrementWriteLatchesAcquired() {
-		writeLatchesAcquired.incrementAndGet();
-	}
+    public void incrementWriteLatchesAcquired() {
+        writeLatchesAcquired.incrementAndGet();
+    }
 
-	public void incrementWriteLatchesReleased() {
-		writeLatchesReleased.incrementAndGet();
-	}
+    public void incrementWriteLatchesReleased() {
+        writeLatchesReleased.incrementAndGet();
+    }
 
-	public void incrementPins() {
-		pins.incrementAndGet();
-	}
+    public void incrementPins() {
+        pins.incrementAndGet();
+    }
 
-	public void incrementUnpins() {
-		unpins.incrementAndGet();
-	}
+    public void incrementUnpins() {
+        unpins.incrementAndGet();
+    }
 
-	public String printStats() {
-		StringBuilder strBuilder = new StringBuilder();
-		strBuilder.append("\n");
-		strBuilder.append("ROOTSPLITS: " + rootSplits + "\n");
-		strBuilder.append("SPLITS BY LEVEL\n");
-		for (int i = 0; i < currentLevel; i++) {
-			strBuilder.append(String.format("%3d ", i)
-					+ String.format("%8d ", splitsByLevel[i]) + "\n");
-		}
-		strBuilder.append(String.format("READ LATCHES:  %10d %10d\n",
-				readLatchesAcquired.get(), readLatchesReleased.get()));
-		strBuilder.append(String.format("WRITE LATCHES: %10d %10d\n",
-				writeLatchesAcquired.get(), writeLatchesReleased.get()));
-		strBuilder.append(String.format("PINS:          %10d %10d\n",
-				pins.get(), unpins.get()));
+    public String printStats() {
+        StringBuilder strBuilder = new StringBuilder();
+        strBuilder.append("\n");
+        strBuilder.append("ROOTSPLITS: " + rootSplits + "\n");
+        strBuilder.append("SPLITS BY LEVEL\n");
+        for (int i = 0; i < currentLevel; i++) {
+            strBuilder.append(String.format("%3d ", i) + String.format("%8d ", splitsByLevel[i]) + "\n");
+        }
+        strBuilder.append(String.format("READ LATCHES:  %10d %10d\n", readLatchesAcquired.get(),
+                readLatchesReleased.get()));
+        strBuilder.append(String.format("WRITE LATCHES: %10d %10d\n", writeLatchesAcquired.get(),
+                writeLatchesReleased.get()));
+        strBuilder.append(String.format("PINS:          %10d %10d\n", pins.get(), unpins.get()));
 
-		strBuilder.append(String.format("Num of Pages:          %10d\n",
-				numOfPages));
+        strBuilder.append(String.format("Num of Pages:          %10d\n", numOfPages));
 
-		return strBuilder.toString();
-	}
+        return strBuilder.toString();
+    }
 
-	public void printTree(IRTreeFrame leafFrame, IRTreeFrame interiorFrame,
-			ISerializerDeserializer[] fields) throws Exception {
-		printTree(rootPage, null, false, leafFrame, interiorFrame, fields);
-	}
+    public void printTree(IRTreeFrame leafFrame, IRTreeFrame interiorFrame, ISerializerDeserializer[] fields)
+            throws Exception {
+        printTree(rootPage, null, false, leafFrame, interiorFrame, fields);
+    }
 
-	public void printTree(int pageId, ICachedPage parent, boolean unpin,
-			IRTreeFrame leafFrame, IRTreeFrame interiorFrame,
-			ISerializerDeserializer[] fields) throws Exception {
+    public void printTree(int pageId, ICachedPage parent, boolean unpin, IRTreeFrame leafFrame,
+            IRTreeFrame interiorFrame, ISerializerDeserializer[] fields) throws Exception {
 
-		ICachedPage node = bufferCache.pin(
-				BufferedFileHandle.getDiskPageId(fileId, pageId), false);
-		incrementPins();
-		node.acquireReadLatch();
-		incrementReadLatchesAcquired();
+        ICachedPage node = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, pageId), false);
+        incrementPins();
+        node.acquireReadLatch();
+        incrementReadLatchesAcquired();
 
-		try {
-			if (parent != null && unpin == true) {
-				parent.releaseReadLatch();
-				incrementReadLatchesReleased();
-				bufferCache.unpin(parent);
-				incrementUnpins();
-			}
+        try {
+            if (parent != null && unpin == true) {
+                parent.releaseReadLatch();
+                incrementReadLatchesReleased();
+                bufferCache.unpin(parent);
+                incrementUnpins();
+            }
 
-			interiorFrame.setPage(node);
-			int level = interiorFrame.getLevel();
+            interiorFrame.setPage(node);
+            int level = interiorFrame.getLevel();
 
-			System.out.format("%1d ", level);
-			System.out.format("%3d ", pageId);
-			for (int i = 0; i < currentLevel - level; i++)
-				System.out.format("    ");
+            System.out.format("%1d ", level);
+            System.out.format("%3d ", pageId);
+            for (int i = 0; i < currentLevel - level; i++)
+                System.out.format("    ");
 
-			String keyString;
-			if (interiorFrame.isLeaf()) {
-				leafFrame.setPage(node);
-				keyString = leafFrame.printKeys(cmp, fields);
-			} else {
-				keyString = interiorFrame.printKeys(cmp, fields);
-			}
+            String keyString;
+            if (interiorFrame.isLeaf()) {
+                leafFrame.setPage(node);
+                keyString = leafFrame.printKeys(cmp, fields);
+            } else {
+                keyString = interiorFrame.printKeys(cmp, fields);
+            }
 
-			System.out.format(keyString);
-			if (!interiorFrame.isLeaf()) {
-				ArrayList<Integer> children = ((RTreeNSMFrame) (interiorFrame))
-						.getChildren(cmp);
-				for (int i = 0; i < children.size(); i++) {
-					printTree(children.get(i), node, i == children.size() - 1,
-							leafFrame, interiorFrame, fields);
-				}
-			} else {
-				node.releaseReadLatch();
-				incrementReadLatchesReleased();
-				bufferCache.unpin(node);
-				incrementUnpins();
-			}
-		} catch (Exception e) {
-			node.releaseReadLatch();
-			incrementReadLatchesReleased();
-			bufferCache.unpin(node);
-			incrementUnpins();
-			throw e;
-		}
-	}
+            System.out.format(keyString);
+            if (!interiorFrame.isLeaf()) {
+                ArrayList<Integer> children = ((RTreeNSMFrame) (interiorFrame)).getChildren(cmp);
+                for (int i = 0; i < children.size(); i++) {
+                    printTree(children.get(i), node, i == children.size() - 1, leafFrame, interiorFrame, fields);
+                }
+            } else {
+                node.releaseReadLatch();
+                incrementReadLatchesReleased();
+                bufferCache.unpin(node);
+                incrementUnpins();
+            }
+        } catch (Exception e) {
+            node.releaseReadLatch();
+            incrementReadLatchesReleased();
+            bufferCache.unpin(node);
+            incrementUnpins();
+            throw e;
+        }
+    }
 
-	@Override
-	public void create(int fileId, ITreeIndexFrame leafFrame,
-			ITreeIndexMetaDataFrame metaFrame) throws Exception {
-		if (created)
-			return;
+    @Override
+    public void create(int fileId, ITreeIndexFrame leafFrame, ITreeIndexMetaDataFrame metaFrame) throws Exception {
+        if (created)
+            return;
 
-		treeLatch.writeLock().lock();
-		try {
-			// check if another thread beat us to it
-			if (created)
-				return;
+        treeLatch.writeLock().lock();
+        try {
+            // check if another thread beat us to it
+            if (created)
+                return;
 
-			freePageManager.init(metaFrame, rootPage);
+            freePageManager.init(metaFrame, rootPage);
 
-			// initialize root page
-			ICachedPage rootNode = bufferCache.pin(
-					BufferedFileHandle.getDiskPageId(fileId, rootPage), true);
-			incrementPins();
+            // initialize root page
+            ICachedPage rootNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), true);
+            incrementPins();
 
-			rootNode.acquireWriteLatch();
-			incrementWriteLatchesAcquired();
-			try {
-				leafFrame.setPage(rootNode);
-				leafFrame.initBuffer((byte) 0);
-			} finally {
-				rootNode.releaseWriteLatch();
-				incrementWriteLatchesReleased();
-				bufferCache.unpin(rootNode);
-				incrementUnpins();
-			}
-			currentLevel = 0;
+            rootNode.acquireWriteLatch();
+            incrementWriteLatchesAcquired();
+            try {
+                leafFrame.setPage(rootNode);
+                leafFrame.initBuffer((byte) 0);
+            } finally {
+                rootNode.releaseWriteLatch();
+                incrementWriteLatchesReleased();
+                bufferCache.unpin(rootNode);
+                incrementUnpins();
+            }
+            currentLevel = 0;
 
-			created = true;
-		} finally {
-			treeLatch.writeLock().unlock();
-		}
-	}
+            created = true;
+        } finally {
+            treeLatch.writeLock().unlock();
+        }
+    }
 
-	public void open(int fileId) {
-		this.fileId = fileId;
-	}
+    public void open(int fileId) {
+        this.fileId = fileId;
+    }
 
-	public void close() {
-		fileId = -1;
-	}
+    public void close() {
+        fileId = -1;
+    }
 
-	@Override
-	public RTreeOpContext createOpContext(IndexOp op,
-			ITreeIndexFrame leafFrame, ITreeIndexFrame interiorFrame,
-			ITreeIndexMetaDataFrame metaFrame) {
-		return new RTreeOpContext(op, (IRTreeLeafFrame) leafFrame,
-				(IRTreeInteriorFrame) interiorFrame, metaFrame, 8);
-	}
+    @Override
+    public RTreeOpContext createOpContext(IndexOp op, ITreeIndexFrame leafFrame, ITreeIndexFrame interiorFrame,
+            ITreeIndexMetaDataFrame metaFrame) {
+        return new RTreeOpContext(op, (IRTreeLeafFrame) leafFrame, (IRTreeInteriorFrame) interiorFrame, metaFrame, 8);
+    }
 
-	@Override
-	public void insert(ITupleReference tuple, IndexOpContext ictx)
-			throws Exception {
-		RTreeOpContext ctx = (RTreeOpContext) ictx;
-		ctx.reset();
-		ctx.setTuple(tuple);
-		ctx.splitKey.reset();
-		ctx.splitKey.getLeftTuple().setFieldCount(cmp.getKeyFieldCount());
-		ctx.splitKey.getRightTuple().setFieldCount(cmp.getKeyFieldCount());
-		ctx.interiorFrame.setPageTupleFieldCount(cmp.getKeyFieldCount());
-		ctx.leafFrame.setPageTupleFieldCount(cmp.getFieldCount());
+    @Override
+    public void insert(ITupleReference tuple, IndexOpContext ictx) throws Exception {
+        RTreeOpContext ctx = (RTreeOpContext) ictx;
+        ctx.reset();
+        ctx.setTuple(tuple);
+        ctx.splitKey.reset();
+        ctx.splitKey.getLeftTuple().setFieldCount(cmp.getKeyFieldCount());
+        ctx.splitKey.getRightTuple().setFieldCount(cmp.getKeyFieldCount());
+        ctx.interiorFrame.setPageTupleFieldCount(cmp.getKeyFieldCount());
+        ctx.leafFrame.setPageTupleFieldCount(cmp.getFieldCount());
 
-		int maxFieldPos = cmp.getKeyFieldCount() / 2;
-		for (int i = 0; i < maxFieldPos; i++) {
-			int j = maxFieldPos + i;
-			int c = cmp.getComparators()[i].compare(tuple.getFieldData(i),
-					tuple.getFieldStart(i), tuple.getFieldLength(i),
-					tuple.getFieldData(j), tuple.getFieldStart(j),
-					tuple.getFieldLength(j));
-			if (c > 0) {
-				throw new IllegalArgumentException(
-						"The low key point has larger coordinates than the high key point.");
-			}
-		}
+        int maxFieldPos = cmp.getKeyFieldCount() / 2;
+        for (int i = 0; i < maxFieldPos; i++) {
+            int j = maxFieldPos + i;
+            int c = cmp.getComparators()[i].compare(tuple.getFieldData(i), tuple.getFieldStart(i),
+                    tuple.getFieldLength(i), tuple.getFieldData(j), tuple.getFieldStart(j), tuple.getFieldLength(j));
+            if (c > 0) {
+                throw new IllegalArgumentException("The low key point has larger coordinates than the high key point.");
+            }
+        }
 
-		ICachedPage leafNode = findLeaf(ctx);
+        ICachedPage leafNode = findLeaf(ctx);
 
-		int pageId = ctx.pathList.getLastPageId();
-		ctx.pathList.moveLast();
-		insertTuple(leafNode, pageId, ctx.getTuple(), ctx, true);
+        int pageId = ctx.pathList.getLastPageId();
+        ctx.pathList.moveLast();
+        insertTuple(leafNode, pageId, ctx.getTuple(), ctx, true);
 
-		while (true) {
-			if (ctx.splitKey.getLeftPageBuffer() != null) {
-				updateParentForInsert(ctx);
-			} else {
-				break;
-			}
-		}
+        while (true) {
+            if (ctx.splitKey.getLeftPageBuffer() != null) {
+                updateParentForInsert(ctx);
+            } else {
+                break;
+            }
+        }
 
-		leafNode.releaseWriteLatch();
-		incrementWriteLatchesReleased();
-		bufferCache.unpin(leafNode);
-		incrementUnpins();
-	}
+        leafNode.releaseWriteLatch();
+        incrementWriteLatchesReleased();
+        bufferCache.unpin(leafNode);
+        incrementUnpins();
+    }
 
-	public ICachedPage findLeaf(RTreeOpContext ctx) throws Exception {
-		int pageId = rootPage;
-		boolean writeLatched = false;
-		ICachedPage node = null;
-		boolean isLeaf = false;
-		int pageLsn = 0, parentLsn = 0;
+    public ICachedPage findLeaf(RTreeOpContext ctx) throws Exception {
+        int pageId = rootPage;
+        boolean writeLatched = false;
+        ICachedPage node = null;
+        boolean isLeaf = false;
+        int pageLsn = 0, parentLsn = 0;
 
-		while (true) {
-			if (!writeLatched) {
-				node = bufferCache
-						.pin(BufferedFileHandle.getDiskPageId(fileId, pageId),
-								false);
-				incrementPins();
-				ctx.interiorFrame.setPage(node);
-				isLeaf = ctx.interiorFrame.isLeaf();
-				if (isLeaf) {
-					node.acquireWriteLatch();
-					incrementWriteLatchesAcquired();
-					writeLatched = true;
+        while (true) {
+            if (!writeLatched) {
+                node = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, pageId), false);
+                incrementPins();
+                ctx.interiorFrame.setPage(node);
+                isLeaf = ctx.interiorFrame.isLeaf();
+                if (isLeaf) {
+                    node.acquireWriteLatch();
+                    incrementWriteLatchesAcquired();
+                    writeLatched = true;
 
-					if (!ctx.interiorFrame.isLeaf()) {
-						node.releaseWriteLatch();
-						incrementWriteLatchesReleased();
-						bufferCache.unpin(node);
-						incrementUnpins();
-						writeLatched = false;
-						continue;
-					}
-				} else {
-					// Be optimistic and grab read latch first. We will swap it
-					// to write latch if we need to enlarge the best child
-					// tuple.
-					node.acquireReadLatch();
-					incrementReadLatchesAcquired();
-				}
-			}
+                    if (!ctx.interiorFrame.isLeaf()) {
+                        node.releaseWriteLatch();
+                        incrementWriteLatchesReleased();
+                        bufferCache.unpin(node);
+                        incrementUnpins();
+                        writeLatched = false;
+                        continue;
+                    }
+                } else {
+                    // Be optimistic and grab read latch first. We will swap it
+                    // to write latch if we need to enlarge the best child
+                    // tuple.
+                    node.acquireReadLatch();
+                    incrementReadLatchesAcquired();
+                }
+            }
 
-			if (pageId != rootPage
-					&& parentLsn < ctx.interiorFrame.getPageNsn()) {
-				// Concurrent split detected, go back to parent and re-choose
-				// the best child
-				if (writeLatched) {
-					node.releaseWriteLatch();
-					incrementWriteLatchesReleased();
-					bufferCache.unpin(node);
-					incrementUnpins();
-					writeLatched = false;
-				} else {
-					node.releaseReadLatch();
-					incrementReadLatchesReleased();
-					bufferCache.unpin(node);
-					incrementUnpins();
-				}
+            if (pageId != rootPage && parentLsn < ctx.interiorFrame.getPageNsn()) {
+                // Concurrent split detected, go back to parent and re-choose
+                // the best child
+                if (writeLatched) {
+                    node.releaseWriteLatch();
+                    incrementWriteLatchesReleased();
+                    bufferCache.unpin(node);
+                    incrementUnpins();
+                    writeLatched = false;
+                } else {
+                    node.releaseReadLatch();
+                    incrementReadLatchesReleased();
+                    bufferCache.unpin(node);
+                    incrementUnpins();
+                }
 
-				pageId = ctx.pathList.getLastPageId();
-				if (pageId != rootPage) {
-					parentLsn = ctx.pathList
-							.getPageLsn(ctx.pathList.size() - 2);
-				}
-				ctx.pathList.moveLast();
-				continue;
-			}
+                pageId = ctx.pathList.getLastPageId();
+                if (pageId != rootPage) {
+                    parentLsn = ctx.pathList.getPageLsn(ctx.pathList.size() - 2);
+                }
+                ctx.pathList.moveLast();
+                continue;
+            }
 
-			pageLsn = ctx.interiorFrame.getPageLsn();
-			ctx.pathList.add(pageId, pageLsn, -1);
+            pageLsn = ctx.interiorFrame.getPageLsn();
+            ctx.pathList.add(pageId, pageLsn, -1);
 
-			if (!isLeaf) {
-				// findBestChild must be called *before* getBestChildPageId
-				ctx.interiorFrame.findBestChild(ctx.getTuple(), cmp);
-				int childPageId = ctx.interiorFrame.getBestChildPageId(cmp);
+            if (!isLeaf) {
+                // findBestChild must be called *before* getBestChildPageId
+                ctx.interiorFrame.findBestChild(ctx.getTuple(), cmp);
+                int childPageId = ctx.interiorFrame.getBestChildPageId(cmp);
 
-				if (!writeLatched) {
-					node.releaseReadLatch();
-					incrementReadLatchesReleased();
-					// TODO: do we need to un-pin and pin again?
-					bufferCache.unpin(node);
-					incrementUnpins();
+                if (!writeLatched) {
+                    node.releaseReadLatch();
+                    incrementReadLatchesReleased();
+                    // TODO: do we need to un-pin and pin again?
+                    bufferCache.unpin(node);
+                    incrementUnpins();
 
-					node = bufferCache.pin(
-							BufferedFileHandle.getDiskPageId(fileId, pageId),
-							false);
-					incrementPins();
-					node.acquireWriteLatch();
-					incrementWriteLatchesAcquired();
-					ctx.interiorFrame.setPage(node);
-					writeLatched = true;
+                    node = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, pageId), false);
+                    incrementPins();
+                    node.acquireWriteLatch();
+                    incrementWriteLatchesAcquired();
+                    ctx.interiorFrame.setPage(node);
+                    writeLatched = true;
 
-					if (ctx.interiorFrame.getPageLsn() != pageLsn) {
-						// The page was changed while we unlocked it; thus,
-						// retry (re-choose best child)
+                    if (ctx.interiorFrame.getPageLsn() != pageLsn) {
+                        // The page was changed while we unlocked it; thus,
+                        // retry (re-choose best child)
 
-						ctx.pathList.moveLast();
-						continue;
-					}
-				}
+                        ctx.pathList.moveLast();
+                        continue;
+                    }
+                }
 
-				// We don't need to reset the frameTuple because it is
-				// already pointing to the best child
-				ctx.interiorFrame.enlarge(ctx.getTuple(), cmp);
+                // We don't need to reset the frameTuple because it is
+                // already pointing to the best child
+                ctx.interiorFrame.enlarge(ctx.getTuple(), cmp);
 
-				node.releaseWriteLatch();
-				incrementWriteLatchesReleased();
-				bufferCache.unpin(node);
-				incrementUnpins();
-				writeLatched = false;
+                node.releaseWriteLatch();
+                incrementWriteLatchesReleased();
+                bufferCache.unpin(node);
+                incrementUnpins();
+                writeLatched = false;
 
-				pageId = childPageId;
-				parentLsn = pageLsn;
-			} else {
-				ctx.leafFrame.setPage(node);
-				return node;
-			}
-		}
-	}
+                pageId = childPageId;
+                parentLsn = pageLsn;
+            } else {
+                ctx.leafFrame.setPage(node);
+                return node;
+            }
+        }
+    }
 
-	private void insertTuple(ICachedPage node, int pageId,
-			ITupleReference tuple, RTreeOpContext ctx, boolean isLeaf)
-			throws Exception {
-		FrameOpSpaceStatus spaceStatus;
-		if (!isLeaf) {
-			spaceStatus = ctx.interiorFrame.hasSpaceInsert(tuple, cmp);
-		} else {
-			spaceStatus = ctx.leafFrame.hasSpaceInsert(tuple, cmp);
-		}
+    private void insertTuple(ICachedPage node, int pageId, ITupleReference tuple, RTreeOpContext ctx, boolean isLeaf)
+            throws Exception {
+    	FrameOpSpaceStatus spaceStatus;
+        if (!isLeaf) {
+            spaceStatus = ctx.interiorFrame.hasSpaceInsert(tuple, cmp);
+        } else {
+            spaceStatus = ctx.leafFrame.hasSpaceInsert(tuple, cmp);
+        }
 
-		switch (spaceStatus) {
-		case SUFFICIENT_CONTIGUOUS_SPACE: {
-			if (!isLeaf) {
-				ctx.interiorFrame.insert(tuple, cmp, -1);
-				incrementGlobalNsn();
-				ctx.interiorFrame.setPageLsn(getGlobalNsn());
-			} else {
-				ctx.leafFrame.insert(tuple, cmp, -1);
-				incrementGlobalNsn();
-				ctx.leafFrame.setPageLsn(getGlobalNsn());
-			}
-			ctx.splitKey.reset();
-			break;
-		}
+        switch (spaceStatus) {
+            case SUFFICIENT_CONTIGUOUS_SPACE: {
+                if (!isLeaf) {
+                    ctx.interiorFrame.insert(tuple, cmp, -1);
+                    incrementGlobalNsn();
+                    ctx.interiorFrame.setPageLsn(getGlobalNsn());
+                } else {
+                    ctx.leafFrame.insert(tuple, cmp, -1);
+                    incrementGlobalNsn();
+                    ctx.leafFrame.setPageLsn(getGlobalNsn());
+                }
+                ctx.splitKey.reset();
+                break;
+            }
 
-		case SUFFICIENT_SPACE: {
-			if (!isLeaf) {
-				ctx.interiorFrame.compact(cmp);
-				ctx.interiorFrame.insert(tuple, cmp, -1);
-				incrementGlobalNsn();
-				ctx.interiorFrame.setPageLsn(getGlobalNsn());
-			} else {
-				ctx.leafFrame.compact(cmp);
-				ctx.leafFrame.insert(tuple, cmp, -1);
-				incrementGlobalNsn();
-				ctx.leafFrame.setPageLsn(getGlobalNsn());
-			}
-			ctx.splitKey.reset();
-			break;
-		}
+            case SUFFICIENT_SPACE: {
+                if (!isLeaf) {
+                    ctx.interiorFrame.compact(cmp);
+                    ctx.interiorFrame.insert(tuple, cmp, -1);
+                    incrementGlobalNsn();
+                    ctx.interiorFrame.setPageLsn(getGlobalNsn());
+                } else {
+                    ctx.leafFrame.compact(cmp);
+                    ctx.leafFrame.insert(tuple, cmp, -1);
+                    incrementGlobalNsn();
+                    ctx.leafFrame.setPageLsn(getGlobalNsn());
+                }
+                ctx.splitKey.reset();
+                break;
+            }
 
-		case INSUFFICIENT_SPACE: {
-			int rightPageId = freePageManager.getFreePage(ctx.metaFrame);
-			ICachedPage rightNode = bufferCache
-					.pin(BufferedFileHandle.getDiskPageId(fileId, rightPageId),
-							true);
-			incrementPins();
-			rightNode.acquireWriteLatch();
-			incrementWriteLatchesAcquired();
+            case INSUFFICIENT_SPACE: {
+                int rightPageId = freePageManager.getFreePage(ctx.metaFrame);
+                ICachedPage rightNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rightPageId), true);
+                incrementPins();
+                rightNode.acquireWriteLatch();
+                incrementWriteLatchesAcquired();
 
-			try {
-				IRTreeFrame rightFrame;
-				int ret;
-				numOfPages++; // debug
-				if (!isLeaf) {
-					splitsByLevel[ctx.interiorFrame.getLevel()]++; // debug
-					rightFrame = (IRTreeFrame) interiorFrameFactory
-							.createFrame();
-					rightFrame.setPage(rightNode);
-					rightFrame.initBuffer((byte) ctx.interiorFrame.getLevel());
-					rightFrame.setPageTupleFieldCount(cmp.getKeyFieldCount());
-					ret = ctx.interiorFrame.split(rightFrame, tuple, cmp,
-							ctx.splitKey);
-					ctx.interiorFrame.setRightPage(rightPageId);
-					rightFrame.setPageNsn(ctx.interiorFrame.getPageNsn());
-					incrementGlobalNsn();
-					int newNsn = getGlobalNsn();
-					rightFrame.setPageLsn(newNsn);
-					ctx.interiorFrame.setPageNsn(newNsn);
-					ctx.interiorFrame.setPageLsn(newNsn);
-				} else {
-					splitsByLevel[0]++; // debug
-					rightFrame = (IRTreeFrame) leafFrameFactory.createFrame();
-					rightFrame.setPage(rightNode);
-					rightFrame.initBuffer((byte) 0);
-					rightFrame.setPageTupleFieldCount(cmp.getFieldCount());
-					ret = ctx.leafFrame.split(rightFrame, tuple, cmp,
-							ctx.splitKey);
-					ctx.leafFrame.setRightPage(rightPageId);
-					rightFrame.setPageNsn(ctx.leafFrame.getPageNsn());
-					incrementGlobalNsn();
-					int newNsn = getGlobalNsn();
-					rightFrame.setPageLsn(newNsn);
-					ctx.leafFrame.setPageNsn(newNsn);
-					ctx.leafFrame.setPageLsn(newNsn);
-				}
-				if (ret != 0) {
-					ctx.splitKey.reset();
-				} else {
-					ctx.splitKey.setPages(pageId, rightPageId);
-				}
-				if (pageId == rootPage) {
-					rootSplits++; // debug
-					splitsByLevel[currentLevel]++;
-					currentLevel++;
+                try {
+                    IRTreeFrame rightFrame;
+                    int ret;
+                    numOfPages++; // debug
+                    if (!isLeaf) {
+                        splitsByLevel[ctx.interiorFrame.getLevel()]++; // debug
+                        rightFrame = (IRTreeFrame) interiorFrameFactory.createFrame();
+                        rightFrame.setPage(rightNode);
+                        rightFrame.initBuffer((byte) ctx.interiorFrame.getLevel());
+                        rightFrame.setPageTupleFieldCount(cmp.getKeyFieldCount());
+                        ret = ctx.interiorFrame.split(rightFrame, tuple, cmp, ctx.splitKey);
+                        ctx.interiorFrame.setRightPage(rightPageId);
+                        rightFrame.setPageNsn(ctx.interiorFrame.getPageNsn());
+                        incrementGlobalNsn();
+                        int newNsn = getGlobalNsn();
+                        rightFrame.setPageLsn(newNsn);
+                        ctx.interiorFrame.setPageNsn(newNsn);
+                        ctx.interiorFrame.setPageLsn(newNsn);
+                    } else {
+                        splitsByLevel[0]++; // debug
+                        rightFrame = (IRTreeFrame) leafFrameFactory.createFrame();
+                        rightFrame.setPage(rightNode);
+                        rightFrame.initBuffer((byte) 0);
+                        rightFrame.setPageTupleFieldCount(cmp.getFieldCount());
+                        ret = ctx.leafFrame.split(rightFrame, tuple, cmp, ctx.splitKey);
+                        ctx.leafFrame.setRightPage(rightPageId);
+                        rightFrame.setPageNsn(ctx.leafFrame.getPageNsn());
+                        incrementGlobalNsn();
+                        int newNsn = getGlobalNsn();
+                        rightFrame.setPageLsn(newNsn);
+                        ctx.leafFrame.setPageNsn(newNsn);
+                        ctx.leafFrame.setPageLsn(newNsn);
+                    }
+                    if (ret != 0) {
+                        ctx.splitKey.reset();
+                    } else {
+                        ctx.splitKey.setPages(pageId, rightPageId);
+                    }
+                    if (pageId == rootPage) {
+                        rootSplits++; // debug
+                        splitsByLevel[currentLevel]++;
+                        currentLevel++;
 
-					int newLeftId = freePageManager.getFreePage(ctx.metaFrame);
-					ICachedPage newLeftNode = bufferCache
-							.pin(BufferedFileHandle.getDiskPageId(fileId,
-									newLeftId), true);
-					incrementPins();
-					newLeftNode.acquireWriteLatch();
-					incrementWriteLatchesAcquired();
-					try {
-						// copy left child to new left child
-						System.arraycopy(node.getBuffer().array(), 0,
-								newLeftNode.getBuffer().array(), 0, newLeftNode
-										.getBuffer().capacity());
+                        int newLeftId = freePageManager.getFreePage(ctx.metaFrame);
+                        ICachedPage newLeftNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, newLeftId),
+                                true);
+                        incrementPins();
+                        newLeftNode.acquireWriteLatch();
+                        incrementWriteLatchesAcquired();
+                        try {
+                            // copy left child to new left child
+                            System.arraycopy(node.getBuffer().array(), 0, newLeftNode.getBuffer().array(), 0,
+                                    newLeftNode.getBuffer().capacity());
 
-						// initialize new root (leftNode becomes new root)
-						ctx.interiorFrame.setPage(node);
-						ctx.interiorFrame.initBuffer((byte) (ctx.interiorFrame
-								.getLevel() + 1));
+                            // initialize new root (leftNode becomes new root)
+                            ctx.interiorFrame.setPage(node);
+                            ctx.interiorFrame.initBuffer((byte) (ctx.interiorFrame.getLevel() + 1));
 
-						ctx.splitKey.setLeftPage(newLeftId);
+                            ctx.splitKey.setLeftPage(newLeftId);
 
-						ctx.interiorFrame.insert(ctx.splitKey.getLeftTuple(),
-								cmp, -1);
-						ctx.interiorFrame.insert(ctx.splitKey.getRightTuple(),
-								cmp, -1);
+                            ctx.interiorFrame.insert(ctx.splitKey.getLeftTuple(), cmp, -1);
+                            ctx.interiorFrame.insert(ctx.splitKey.getRightTuple(), cmp, -1);
 
-						incrementGlobalNsn();
-						int newNsn = getGlobalNsn();
-						ctx.interiorFrame.setPageLsn(newNsn);
-						ctx.interiorFrame.setPageNsn(newNsn);
-					} finally {
-						newLeftNode.releaseWriteLatch();
-						incrementWriteLatchesReleased();
-						bufferCache.unpin(newLeftNode);
-						incrementUnpins();
-					}
+                            incrementGlobalNsn();
+                            int newNsn = getGlobalNsn();
+                            ctx.interiorFrame.setPageLsn(newNsn);
+                            ctx.interiorFrame.setPageNsn(newNsn);
+                        } finally {
+                            newLeftNode.releaseWriteLatch();
+                            incrementWriteLatchesReleased();
+                            bufferCache.unpin(newLeftNode);
+                            incrementUnpins();
+                        }
 
-					ctx.splitKey.reset();
-				}
-			} finally {
-				rightNode.releaseWriteLatch();
-				incrementWriteLatchesReleased();
-				bufferCache.unpin(rightNode);
-				incrementUnpins();
-			}
-			break;
-		}
-		}
-	}
+                        ctx.splitKey.reset();
+                    }
+                } finally {
+                    rightNode.releaseWriteLatch();
+                    incrementWriteLatchesReleased();
+                    bufferCache.unpin(rightNode);
+                    incrementUnpins();
+                }
+                break;
+            }
+        }
+    }
 
-	public void updateParentForInsert(RTreeOpContext ctx) throws Exception {
-		int parentId = ctx.pathList.getLastPageId();
-		ICachedPage parentNode = bufferCache.pin(
-				BufferedFileHandle.getDiskPageId(fileId, parentId), false);
-		incrementPins();
-		parentNode.acquireWriteLatch();
-		incrementWriteLatchesAcquired();
-		ctx.interiorFrame.setPage(parentNode);
-		boolean foundParent = true;
+    public void updateParentForInsert(RTreeOpContext ctx) throws Exception {
+        int parentId = ctx.pathList.getLastPageId();
+        ICachedPage parentNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, parentId), false);
+        incrementPins();
+        parentNode.acquireWriteLatch();
+        incrementWriteLatchesAcquired();
+        ctx.interiorFrame.setPage(parentNode);
+        boolean foundParent = true;
 
-		if (ctx.interiorFrame.getPageLsn() != ctx.pathList.getLastPageLsn()) {
-			foundParent = false;
-			while (true) {
-				if (ctx.interiorFrame.findTupleByPointer(
-						ctx.splitKey.getLeftTuple(), cmp) != -1) {
-					// found the parent
-					foundParent = true;
-					break;
-				}
-				int rightPage = ctx.interiorFrame.getRightPage();
-				parentNode.releaseWriteLatch();
-				incrementWriteLatchesReleased();
-				bufferCache.unpin(parentNode);
-				incrementUnpins();
+        if (ctx.interiorFrame.getPageLsn() != ctx.pathList.getLastPageLsn()) {
+            foundParent = false;
+            while (true) {
+                if (ctx.interiorFrame.findTupleByPointer(ctx.splitKey.getLeftTuple(), cmp) != -1) {
+                    // found the parent
+                    foundParent = true;
+                    break;
+                }
+                int rightPage = ctx.interiorFrame.getRightPage();
+                parentNode.releaseWriteLatch();
+                incrementWriteLatchesReleased();
+                bufferCache.unpin(parentNode);
+                incrementUnpins();
 
-				if (rightPage == -1) {
-					break;
-				}
+                if (rightPage == -1) {
+                    break;
+                }
 
-				parentId = rightPage;
-				parentNode = bufferCache.pin(
-						BufferedFileHandle.getDiskPageId(fileId, parentId),
-						false);
-				incrementPins();
-				parentNode.acquireWriteLatch();
-				incrementWriteLatchesAcquired();
-				ctx.interiorFrame.setPage(parentNode);
-			}
-		}
-		if (foundParent) {
-			ctx.interiorFrame.adjustKey(ctx.splitKey.getLeftTuple(), -1, cmp);
-			insertTuple(parentNode, parentId, ctx.splitKey.getRightTuple(),
-					ctx, ctx.interiorFrame.isLeaf());
-			ctx.pathList.moveLast();
+                parentId = rightPage;
+                parentNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, parentId), false);
+                incrementPins();
+                parentNode.acquireWriteLatch();
+                incrementWriteLatchesAcquired();
+                ctx.interiorFrame.setPage(parentNode);
+            }
+        }
+        if (foundParent) {
+            ctx.interiorFrame.adjustKey(ctx.splitKey.getLeftTuple(), -1, cmp);
+            insertTuple(parentNode, parentId, ctx.splitKey.getRightTuple(), ctx, ctx.interiorFrame.isLeaf());
+            ctx.pathList.moveLast();
 
-			parentNode.releaseWriteLatch();
-			incrementWriteLatchesReleased();
-			bufferCache.unpin(parentNode);
-			incrementUnpins();
-			return;
-		}
+            parentNode.releaseWriteLatch();
+            incrementWriteLatchesReleased();
+            bufferCache.unpin(parentNode);
+            incrementUnpins();
+            return;
+        }
 
-		// very rare situation when the there is a root split, do an exhaustive
-		// breadth-first traversal looking for the parent tuple
+        // very rare situation when the there is a root split, do an exhaustive
+        // breadth-first traversal looking for the parent tuple
 
-		ctx.pathList.clear();
-		ctx.traverseList.clear();
-		findPath(ctx);
-		updateParentForInsert(ctx);
-	}
+        ctx.pathList.clear();
+        ctx.traverseList.clear();
+        findPath(ctx);
+        updateParentForInsert(ctx);
+    }
 
-	public void findPath(RTreeOpContext ctx) throws Exception {
-		int pageId = rootPage;
-		int parentIndex = -1;
-		int parentLsn = 0;
-		int pageLsn, pageIndex;
-		ctx.traverseList.add(pageId, -1, parentIndex);
-		while (!ctx.traverseList.isLast()) {
-			pageId = ctx.traverseList.getFirstPageId();
-			parentIndex = ctx.traverseList.getFirstPageIndex();
+    public void findPath(RTreeOpContext ctx) throws Exception {
+        int pageId = rootPage;
+        int parentIndex = -1;
+        int parentLsn = 0;
+        int pageLsn, pageIndex;
+        ctx.traverseList.add(pageId, -1, parentIndex);
+        while (!ctx.traverseList.isLast()) {
+            pageId = ctx.traverseList.getFirstPageId();
+            parentIndex = ctx.traverseList.getFirstPageIndex();
 
-			ICachedPage node = bufferCache.pin(
-					BufferedFileHandle.getDiskPageId(fileId, pageId), false);
-			incrementPins();
-			node.acquireReadLatch();
-			incrementReadLatchesAcquired();
-			ctx.interiorFrame.setPage(node);
-			pageLsn = ctx.interiorFrame.getPageLsn();
-			pageIndex = ctx.traverseList.first();
-			ctx.traverseList.setPageLsn(pageIndex, pageLsn);
+            ICachedPage node = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, pageId), false);
+            incrementPins();
+            node.acquireReadLatch();
+            incrementReadLatchesAcquired();
+            ctx.interiorFrame.setPage(node);
+            pageLsn = ctx.interiorFrame.getPageLsn();
+            pageIndex = ctx.traverseList.first();
+            ctx.traverseList.setPageLsn(pageIndex, pageLsn);
 
-			ctx.traverseList.moveFirst();
+            ctx.traverseList.moveFirst();
 
-			if (pageId != rootPage
-					&& parentLsn < ctx.interiorFrame.getPageNsn()) {
-				int rightPage = ctx.interiorFrame.getRightPage();
-				if (rightPage != -1) {
-					ctx.traverseList.add(rightPage, -1, parentIndex);
-				}
-			}
-			parentLsn = pageLsn;
+            if (pageId != rootPage && parentLsn < ctx.interiorFrame.getPageNsn()) {
+                int rightPage = ctx.interiorFrame.getRightPage();
+                if (rightPage != -1) {
+                    ctx.traverseList.add(rightPage, -1, parentIndex);
+                }
+            }
+            parentLsn = pageLsn;
 
-			if (ctx.interiorFrame.findTupleByPointer(
-					ctx.splitKey.getLeftTuple(), ctx.traverseList, pageIndex,
-					cmp) != -1) {
-				fillPath(ctx, pageIndex);
+            if (ctx.interiorFrame.findTupleByPointer(ctx.splitKey.getLeftTuple(), ctx.traverseList, pageIndex, cmp) != -1) {
+                fillPath(ctx, pageIndex);
 
-				node.releaseReadLatch();
-				incrementReadLatchesReleased();
-				bufferCache.unpin(node);
-				incrementUnpins();
-				return;
-			}
-			node.releaseReadLatch();
-			incrementReadLatchesReleased();
-			bufferCache.unpin(node);
-			incrementUnpins();
-		}
-	}
+                node.releaseReadLatch();
+                incrementReadLatchesReleased();
+                bufferCache.unpin(node);
+                incrementUnpins();
+                return;
+            }
+            node.releaseReadLatch();
+            incrementReadLatchesReleased();
+            bufferCache.unpin(node);
+            incrementUnpins();
+        }
+    }
 
-	public void fillPath(RTreeOpContext ctx, int pageIndex) throws Exception {
-		if (pageIndex != -1) {
-			fillPath(ctx, ctx.traverseList.getPageIndex(pageIndex));
-			ctx.pathList.add(ctx.traverseList.getPageId(pageIndex),
-					ctx.traverseList.getPageLsn(pageIndex), -1);
-		}
-	}
+    public void fillPath(RTreeOpContext ctx, int pageIndex) throws Exception {
+        if (pageIndex != -1) {
+            fillPath(ctx, ctx.traverseList.getPageIndex(pageIndex));
+            ctx.pathList.add(ctx.traverseList.getPageId(pageIndex), ctx.traverseList.getPageLsn(pageIndex), -1);
+        }
+    }
 
-	@Override
-	public void delete(ITupleReference tuple, IndexOpContext ictx)
-			throws Exception {
-		RTreeOpContext ctx = (RTreeOpContext) ictx;
-		ctx.reset();
-		ctx.setTuple(tuple);
-		ctx.splitKey.reset();
-		ctx.splitKey.getLeftTuple().setFieldCount(cmp.getKeyFieldCount());
-		ctx.interiorFrame.setPageTupleFieldCount(cmp.getKeyFieldCount());
-		ctx.leafFrame.setPageTupleFieldCount(cmp.getFieldCount());
+    @Override
+    public void delete(ITupleReference tuple, IndexOpContext ictx) throws Exception {
+        RTreeOpContext ctx = (RTreeOpContext) ictx;
+        ctx.reset();
+        ctx.setTuple(tuple);
+        ctx.splitKey.reset();
+        ctx.splitKey.getLeftTuple().setFieldCount(cmp.getKeyFieldCount());
+        ctx.interiorFrame.setPageTupleFieldCount(cmp.getKeyFieldCount());
+        ctx.leafFrame.setPageTupleFieldCount(cmp.getFieldCount());
 
-		int tupleIndex = findTupleToDelete(ctx);
+        int tupleIndex = findTupleToDelete(ctx);
 
-		if (tupleIndex != -1) {
-			int pageId = ctx.pathList.getLastPageId();
-			ctx.pathList.moveLast();
-			deleteTuple(pageId, tupleIndex, ctx);
+        if (tupleIndex != -1) {
+            int pageId = ctx.pathList.getLastPageId();
+            ctx.pathList.moveLast();
+            deleteTuple(pageId, tupleIndex, ctx);
 
-			while (true) {
-				if (ctx.splitKey.getLeftPageBuffer() != null) {
-					updateParentForDelete(ctx);
-				} else {
-					break;
-				}
-			}
+            while (true) {
+                if (ctx.splitKey.getLeftPageBuffer() != null) {
+                    updateParentForDelete(ctx);
+                } else {
+                    break;
+                }
+            }
 
-			ctx.leafFrame.getPage().releaseWriteLatch();
-			incrementWriteLatchesReleased();
-			bufferCache.unpin(ctx.leafFrame.getPage());
-			incrementUnpins();
-		}
-	}
+            ctx.leafFrame.getPage().releaseWriteLatch();
+            incrementWriteLatchesReleased();
+            bufferCache.unpin(ctx.leafFrame.getPage());
+            incrementUnpins();
+        }
+    }
 
-	public void updateParentForDelete(RTreeOpContext ctx) throws Exception {
-		int parentId = ctx.pathList.getLastPageId();
-		ICachedPage parentNode = bufferCache.pin(
-				BufferedFileHandle.getDiskPageId(fileId, parentId), false);
-		incrementPins();
-		parentNode.acquireWriteLatch();
-		incrementWriteLatchesAcquired();
-		ctx.interiorFrame.setPage(parentNode);
-		boolean foundParent = true;
-		int tupleIndex = -1;
+    public void updateParentForDelete(RTreeOpContext ctx) throws Exception {
+        int parentId = ctx.pathList.getLastPageId();
+        ICachedPage parentNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, parentId), false);
+        incrementPins();
+        parentNode.acquireWriteLatch();
+        incrementWriteLatchesAcquired();
+        ctx.interiorFrame.setPage(parentNode);
+        boolean foundParent = true;
+        int tupleIndex = -1;
 
-		if (ctx.interiorFrame.getPageLsn() != ctx.pathList.getLastPageLsn()) {
-			foundParent = false;
-			while (true) {
-				tupleIndex = ctx.interiorFrame.findTupleByPointer(
-						ctx.splitKey.getLeftTuple(), cmp);
-				if (tupleIndex != -1) {
-					// found the parent
-					foundParent = true;
-					break;
-				}
-				int rightPage = ctx.interiorFrame.getRightPage();
-				parentNode.releaseWriteLatch();
-				incrementWriteLatchesReleased();
-				bufferCache.unpin(parentNode);
-				incrementUnpins();
+        if (ctx.interiorFrame.getPageLsn() != ctx.pathList.getLastPageLsn()) {
+            foundParent = false;
+            while (true) {
+                tupleIndex = ctx.interiorFrame.findTupleByPointer(ctx.splitKey.getLeftTuple(), cmp);
+                if (tupleIndex != -1) {
+                    // found the parent
+                    foundParent = true;
+                    break;
+                }
+                int rightPage = ctx.interiorFrame.getRightPage();
+                parentNode.releaseWriteLatch();
+                incrementWriteLatchesReleased();
+                bufferCache.unpin(parentNode);
+                incrementUnpins();
 
-				if (rightPage == -1) {
-					break;
-				}
+                if (rightPage == -1) {
+                    break;
+                }
 
-				parentId = rightPage;
-				parentNode = bufferCache.pin(
-						BufferedFileHandle.getDiskPageId(fileId, parentId),
-						false);
-				incrementPins();
-				parentNode.acquireWriteLatch();
-				incrementWriteLatchesAcquired();
-				ctx.interiorFrame.setPage(parentNode);
-			}
-		}
-		if (foundParent) {
-			if (tupleIndex == -1) {
-				tupleIndex = ctx.interiorFrame.findTupleByPointer(
-						ctx.splitKey.getLeftTuple(), cmp);
-			}
-			boolean recomputeMBR = ctx.interiorFrame.recomputeMBR(
-					ctx.splitKey.getLeftTuple(), tupleIndex, cmp);
+                parentId = rightPage;
+                parentNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, parentId), false);
+                incrementPins();
+                parentNode.acquireWriteLatch();
+                incrementWriteLatchesAcquired();
+                ctx.interiorFrame.setPage(parentNode);
+            }
+        }
+        if (foundParent) {
+            if (tupleIndex == -1) {
+                tupleIndex = ctx.interiorFrame.findTupleByPointer(ctx.splitKey.getLeftTuple(), cmp);
+            }
+            boolean recomputeMBR = ctx.interiorFrame.recomputeMBR(ctx.splitKey.getLeftTuple(), tupleIndex, cmp);
 
-			if (recomputeMBR) {
-				ctx.interiorFrame.adjustKey(ctx.splitKey.getLeftTuple(),
-						tupleIndex, cmp);
-				ctx.pathList.moveLast();
+            if (recomputeMBR) {
+                ctx.interiorFrame.adjustKey(ctx.splitKey.getLeftTuple(), tupleIndex, cmp);
+                ctx.pathList.moveLast();
 
-				incrementGlobalNsn();
-				ctx.interiorFrame.setPageLsn(getGlobalNsn());
+                incrementGlobalNsn();
+                ctx.interiorFrame.setPageLsn(getGlobalNsn());
 
-				ctx.splitKey.reset();
-				if (!ctx.pathList.isEmpty()) {
-					ctx.interiorFrame.computeMBR(ctx.splitKey, cmp);
-					ctx.splitKey.setLeftPage(parentId);
-				}
-			} else {
-				ctx.pathList.moveLast();
-				ctx.splitKey.reset();
-			}
+                ctx.splitKey.reset();
+                if (!ctx.pathList.isEmpty()) {
+                    ctx.interiorFrame.computeMBR(ctx.splitKey, cmp);
+                    ctx.splitKey.setLeftPage(parentId);
+                }
+            } else {
+                ctx.pathList.moveLast();
+                ctx.splitKey.reset();
+            }
 
-			parentNode.releaseWriteLatch();
-			incrementWriteLatchesReleased();
-			bufferCache.unpin(parentNode);
-			incrementUnpins();
-			return;
-		}
+            parentNode.releaseWriteLatch();
+            incrementWriteLatchesReleased();
+            bufferCache.unpin(parentNode);
+            incrementUnpins();
+            return;
+        }
 
-		// very rare situation when the there is a root split, do an exhaustive
-		// breadth-first traversal looking for the parent tuple
+        // very rare situation when the there is a root split, do an exhaustive
+        // breadth-first traversal looking for the parent tuple
 
-		ctx.pathList.clear();
-		ctx.traverseList.clear();
-		findPath(ctx);
-		updateParentForDelete(ctx);
-	}
+        ctx.pathList.clear();
+        ctx.traverseList.clear();
+        findPath(ctx);
+        updateParentForDelete(ctx);
+    }
 
-	public int findTupleToDelete(RTreeOpContext ctx) throws Exception {
+    public int findTupleToDelete(RTreeOpContext ctx) throws Exception {
 
-		ctx.traverseList.add(rootPage, -1, -1);
-		ctx.pathList.add(rootPage, -1, ctx.traverseList.size() - 1);
+        ctx.traverseList.add(rootPage, -1, -1);
+        ctx.pathList.add(rootPage, -1, ctx.traverseList.size() - 1);
 
-		while (!ctx.pathList.isEmpty()) {
-			int pageId = ctx.pathList.getLastPageId();
-			int parentLsn = ctx.pathList.getLastPageLsn();
-			int pageIndex = ctx.pathList.getLastPageIndex();
-			ctx.pathList.moveLast();
-			ICachedPage node = bufferCache.pin(
-					BufferedFileHandle.getDiskPageId(fileId, pageId), false);
-			incrementPins();
-			node.acquireReadLatch();
-			incrementReadLatchesAcquired();
-			ctx.interiorFrame.setPage(node);
-			boolean isLeaf = ctx.interiorFrame.isLeaf();
-			int pageLsn = ctx.interiorFrame.getPageLsn();
-			int parentIndex = ctx.traverseList.getPageIndex(pageIndex);
-			ctx.traverseList.setPageLsn(pageIndex, pageLsn);
+        while (!ctx.pathList.isEmpty()) {
+            int pageId = ctx.pathList.getLastPageId();
+            int parentLsn = ctx.pathList.getLastPageLsn();
+            int pageIndex = ctx.pathList.getLastPageIndex();
+            ctx.pathList.moveLast();
+            ICachedPage node = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, pageId), false);
+            incrementPins();
+            node.acquireReadLatch();
+            incrementReadLatchesAcquired();
+            ctx.interiorFrame.setPage(node);
+            boolean isLeaf = ctx.interiorFrame.isLeaf();
+            int pageLsn = ctx.interiorFrame.getPageLsn();
+            int parentIndex = ctx.traverseList.getPageIndex(pageIndex);
+            ctx.traverseList.setPageLsn(pageIndex, pageLsn);
 
-			if (pageId != rootPage
-					&& parentLsn < ctx.interiorFrame.getPageNsn()) {
-				// Concurrent split detected, we need to visit the right page
-				int rightPage = ctx.interiorFrame.getRightPage();
-				if (rightPage != -1) {
-					ctx.traverseList.add(rightPage, -1, parentIndex);
-					ctx.pathList.add(rightPage, parentLsn,
-							ctx.traverseList.size() - 1);
-				}
-			}
+            if (pageId != rootPage && parentLsn < ctx.interiorFrame.getPageNsn()) {
+                // Concurrent split detected, we need to visit the right page
+                int rightPage = ctx.interiorFrame.getRightPage();
+                if (rightPage != -1) {
+                    ctx.traverseList.add(rightPage, -1, parentIndex);
+                    ctx.pathList.add(rightPage, parentLsn, ctx.traverseList.size() - 1);
+                }
+            }
 
-			if (!isLeaf) {
-				for (int i = 0; i < ctx.interiorFrame.getTupleCount(); i++) {
-					int childPageId = ctx.interiorFrame
-							.getChildPageIdIfIntersect(ctx.tuple, i, cmp);
-					if (childPageId != -1) {
-						ctx.traverseList.add(childPageId, -1, pageIndex);
-						ctx.pathList.add(childPageId, pageLsn,
-								ctx.traverseList.size() - 1);
-					}
-				}
-			} else {
-				ctx.leafFrame.setPage(node);
-				int tupleIndex = ctx.leafFrame.findTupleIndex(ctx.tuple, cmp);
-				if (tupleIndex != -1) {
+            if (!isLeaf) {
+                for (int i = 0; i < ctx.interiorFrame.getTupleCount(); i++) {
+                    int childPageId = ctx.interiorFrame.getChildPageIdIfIntersect(ctx.tuple, i, cmp);
+                    if (childPageId != -1) {
+                        ctx.traverseList.add(childPageId, -1, pageIndex);
+                        ctx.pathList.add(childPageId, pageLsn, ctx.traverseList.size() - 1);
+                    }
+                }
+            } else {
+                ctx.leafFrame.setPage(node);
+                int tupleIndex = ctx.leafFrame.findTupleIndex(ctx.tuple, cmp);
+                if (tupleIndex != -1) {
 
-					node.releaseReadLatch();
-					incrementReadLatchesReleased();
-					bufferCache.unpin(node);
-					incrementUnpins();
+                    node.releaseReadLatch();
+                    incrementReadLatchesReleased();
+                    bufferCache.unpin(node);
+                    incrementUnpins();
 
-					node = bufferCache.pin(
-							BufferedFileHandle.getDiskPageId(fileId, pageId),
-							false);
-					incrementPins();
-					node.acquireWriteLatch();
-					incrementWriteLatchesAcquired();
-					ctx.leafFrame.setPage(node);
+                    node = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, pageId), false);
+                    incrementPins();
+                    node.acquireWriteLatch();
+                    incrementWriteLatchesAcquired();
+                    ctx.leafFrame.setPage(node);
 
-					if (ctx.leafFrame.getPageLsn() != pageLsn) {
-						// The page was changed while we unlocked it
+                    if (ctx.leafFrame.getPageLsn() != pageLsn) {
+                        // The page was changed while we unlocked it
 
-						tupleIndex = ctx.leafFrame.findTupleIndex(ctx.tuple,
-								cmp);
-						if (tupleIndex == -1) {
-							ctx.traverseList.add(pageId, -1, parentIndex);
-							ctx.pathList.add(pageId, parentLsn,
-									ctx.traverseList.size() - 1);
+                        tupleIndex = ctx.leafFrame.findTupleIndex(ctx.tuple, cmp);
+                        if (tupleIndex == -1) {
+                            ctx.traverseList.add(pageId, -1, parentIndex);
+                            ctx.pathList.add(pageId, parentLsn, ctx.traverseList.size() - 1);
 
-							node.releaseWriteLatch();
-							incrementWriteLatchesReleased();
-							bufferCache.unpin(node);
-							incrementUnpins();
-							continue;
-						} else {
-							ctx.pathList.clear();
-							fillPath(ctx, pageIndex);
-							return tupleIndex;
-						}
-					} else {
-						ctx.pathList.clear();
-						fillPath(ctx, pageIndex);
-						return tupleIndex;
-					}
-				}
-			}
-			node.releaseReadLatch();
-			incrementReadLatchesReleased();
-			bufferCache.unpin(node);
-			incrementUnpins();
-		}
-		return -1;
-	}
+                            node.releaseWriteLatch();
+                            incrementWriteLatchesReleased();
+                            bufferCache.unpin(node);
+                            incrementUnpins();
+                            continue;
+                        } else {
+                            ctx.pathList.clear();
+                            fillPath(ctx, pageIndex);
+                            return tupleIndex;
+                        }
+                    } else {
+                        ctx.pathList.clear();
+                        fillPath(ctx, pageIndex);
+                        return tupleIndex;
+                    }
+                }
+            }
+            node.releaseReadLatch();
+            incrementReadLatchesReleased();
+            bufferCache.unpin(node);
+            incrementUnpins();
+        }
+        return -1;
+    }
 
-	public void deleteTuple(int pageId, int tupleIndex, RTreeOpContext ctx)
-			throws Exception {
-		ctx.leafFrame.delete(tupleIndex, cmp);
-		incrementGlobalNsn();
-		ctx.leafFrame.setPageLsn(getGlobalNsn());
+    public void deleteTuple(int pageId, int tupleIndex, RTreeOpContext ctx) throws Exception {
+        ctx.leafFrame.delete(tupleIndex, cmp);
+        incrementGlobalNsn();
+        ctx.leafFrame.setPageLsn(getGlobalNsn());
 
-		// if the page is empty, just leave it there for future inserts
-		if (pageId != rootPage && ctx.leafFrame.getTupleCount() > 0) {
-			ctx.leafFrame.computeMBR(ctx.splitKey, cmp);
-			ctx.splitKey.setLeftPage(pageId);
-		}
-	}
+        // if the page is empty, just leave it there for future inserts
+        if (pageId != rootPage && ctx.leafFrame.getTupleCount() > 0) {
+            ctx.leafFrame.computeMBR(ctx.splitKey, cmp);
+            ctx.splitKey.setLeftPage(pageId);
+        }
+    }
 
-	public void search(ITreeIndexCursor cursor, SearchPredicate pred,
-			RTreeOpContext ctx) throws Exception {
-		ctx.reset();
-		ctx.cursor = cursor;
+    public void search(ITreeIndexCursor cursor, SearchPredicate pred, RTreeOpContext ctx) throws Exception {
+        ctx.reset();
+        ctx.cursor = cursor;
 
-		cursor.setBufferCache(bufferCache);
-		cursor.setFileId(fileId);
-		ctx.cursorInitialState.setRootPage(rootPage);
-		ctx.cursor.open(ctx.cursorInitialState, pred);
-	}
+        cursor.setBufferCache(bufferCache);
+        cursor.setFileId(fileId);
+        ctx.cursorInitialState.setRootPage(rootPage);
+        ctx.cursor.open(ctx.cursorInitialState, pred);
+    }
 
-	public ITreeIndexFrameFactory getInteriorFrameFactory() {
-		return interiorFrameFactory;
-	}
+    public ITreeIndexFrameFactory getInteriorFrameFactory() {
+        return interiorFrameFactory;
+    }
 
-	public ITreeIndexFrameFactory getLeafFrameFactory() {
-		return leafFrameFactory;
-	}
+    public ITreeIndexFrameFactory getLeafFrameFactory() {
+        return leafFrameFactory;
+    }
 
-	public MultiComparator getCmp() {
-		return cmp;
-	}
+    public MultiComparator getCmp() {
+        return cmp;
+    }
 
-	public IFreePageManager getFreePageManager() {
-		return freePageManager;
-	}
+    public IFreePageManager getFreePageManager() {
+        return freePageManager;
+    }
 
-	@Override
-	public void update(ITupleReference tuple, IndexOpContext ictx)
-			throws Exception {
-		throw new Exception("RTree Update not implemented.");
-	}
+    @Override
+    public void update(ITupleReference tuple, IndexOpContext ictx) throws Exception {
+        throw new Exception("RTree Update not implemented.");
+    }
 
-	public final class BulkLoadContext implements IIndexBulkLoadContext {
+    public final class BulkLoadContext implements IIndexBulkLoadContext {
 
-		public RTreeOpContext insertOpCtx;
+        public RTreeOpContext insertOpCtx;
 
-		public BulkLoadContext(float fillFactor, IRTreeFrame leafFrame,
-				IRTreeFrame interiorFrame, ITreeIndexMetaDataFrame metaFrame)
-				throws HyracksDataException {
+        public BulkLoadContext(float fillFactor, IRTreeFrame leafFrame, IRTreeFrame interiorFrame,
+                ITreeIndexMetaDataFrame metaFrame) throws HyracksDataException {
 
-			insertOpCtx = createOpContext(IndexOp.INSERT, leafFrame,
-					interiorFrame, metaFrame);
-		}
-	}
+            insertOpCtx = createOpContext(IndexOp.INSERT, leafFrame, interiorFrame, metaFrame);
+        }
+    }
 
-	@Override
-	public IIndexBulkLoadContext beginBulkLoad(float fillFactor,
-			ITreeIndexFrame leafFrame, ITreeIndexFrame interiorFrame,
-			ITreeIndexMetaDataFrame metaFrame) throws HyracksDataException {
-		if (loaded)
-			throw new HyracksDataException(
-					"Trying to bulk-load RTree but RTree has already been loaded.");
+    @Override
+    public IIndexBulkLoadContext beginBulkLoad(float fillFactor, ITreeIndexFrame leafFrame,
+            ITreeIndexFrame interiorFrame, ITreeIndexMetaDataFrame metaFrame) throws HyracksDataException {
+        if (loaded)
+            throw new HyracksDataException("Trying to bulk-load RTree but RTree has already been loaded.");
 
-		BulkLoadContext ctx = new BulkLoadContext(fillFactor,
-				(IRTreeFrame) leafFrame, (IRTreeFrame) interiorFrame, metaFrame);
-		return ctx;
-	}
+        BulkLoadContext ctx = new BulkLoadContext(fillFactor, (IRTreeFrame) leafFrame, (IRTreeFrame) interiorFrame,
+                metaFrame);
+        return ctx;
+    }
 
-	@Override
-	public void bulkLoadAddTuple(IIndexBulkLoadContext ictx,
-			ITupleReference tuple) throws HyracksDataException {
-		try {
-			insert(tuple, ((BulkLoadContext) ictx).insertOpCtx);
-		} catch (Exception e) {
-			throw new HyracksDataException("BulkLoad Error");
-		}
-	}
+    @Override
+    public void bulkLoadAddTuple(IIndexBulkLoadContext ictx, ITupleReference tuple) throws HyracksDataException {
+        try {
+            insert(tuple, ((BulkLoadContext) ictx).insertOpCtx);
+        } catch (Exception e) {
+            throw new HyracksDataException("BulkLoad Error");
+        }
+    }
 
-	@Override
-	public void endBulkLoad(IIndexBulkLoadContext ictx)
-			throws HyracksDataException {
-		loaded = true;
-	}
+    @Override
+    public void endBulkLoad(IIndexBulkLoadContext ictx) throws HyracksDataException {
+        loaded = true;
+    }
 
-	@Override
-	public void diskOrderScan(ITreeIndexCursor icursor,
-			ITreeIndexFrame leafFrame, ITreeIndexMetaDataFrame metaFrame,
-			IndexOpContext ictx) throws HyracksDataException {
-		TreeDiskOrderScanCursor cursor = (TreeDiskOrderScanCursor) icursor;
-		RTreeOpContext ctx = (RTreeOpContext) ictx;
-		ctx.reset();
+    @Override
+    public void diskOrderScan(ITreeIndexCursor icursor, ITreeIndexFrame leafFrame, ITreeIndexMetaDataFrame metaFrame,
+            IndexOpContext ictx) throws HyracksDataException {
+        TreeDiskOrderScanCursor cursor = (TreeDiskOrderScanCursor) icursor;
+        RTreeOpContext ctx = (RTreeOpContext) ictx;
+        ctx.reset();
 
-		int currentPageId = rootPage + 1;
-		int maxPageId = freePageManager.getMaxPage(metaFrame);
+        int currentPageId = rootPage + 1;
+        int maxPageId = freePageManager.getMaxPage(metaFrame);
 
-		ICachedPage page = bufferCache.pin(
-				BufferedFileHandle.getDiskPageId(fileId, currentPageId), false);
-		page.acquireReadLatch();
-		cursor.setBufferCache(bufferCache);
-		cursor.setFileId(fileId);
-		cursor.setCurrentPageId(currentPageId);
-		cursor.setMaxPageId(maxPageId);
-		ctx.cursorInitialState.setPage(page);
-		cursor.open(ctx.cursorInitialState, diskOrderScanPredicate);
-	}
+        ICachedPage page = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, currentPageId), false);
+        page.acquireReadLatch();
+        cursor.setBufferCache(bufferCache);
+        cursor.setFileId(fileId);
+        cursor.setCurrentPageId(currentPageId);
+        cursor.setMaxPageId(maxPageId);
+        ctx.cursorInitialState.setPage(page);
+        cursor.open(ctx.cursorInitialState, diskOrderScanPredicate);
+    }
 
-	@Override
-	public int getRootPageId() {
-		return rootPage;
-	}
+    @Override
+    public int getRootPageId() {
+        return rootPage;
+    }
 
-	@Override
-	public int getFieldCount() {
-		return cmp.getFieldCount();
-	}
+    @Override
+    public int getFieldCount() {
+        return cmp.getFieldCount();
+    }
 
-	@Override
-	public IndexType getIndexType() {
-		return IndexType.RTREE;
-	}
-}
\ No newline at end of file
+    @Override
+    public IndexType getIndexType() {
+        return IndexType.RTREE;
+    }
+}
diff --git a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/tuples/RTreeTypeAwareTupleWriter.java b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/tuples/RTreeTypeAwareTupleWriter.java
index 6acac7e..244c69e 100644
--- a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/tuples/RTreeTypeAwareTupleWriter.java
+++ b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/tuples/RTreeTypeAwareTupleWriter.java
@@ -23,36 +23,35 @@
 
 public class RTreeTypeAwareTupleWriter extends TypeAwareTupleWriter {
 
-	public RTreeTypeAwareTupleWriter(ITypeTrait[] typeTraits) {
-		super(typeTraits);
-	}
+    public RTreeTypeAwareTupleWriter(ITypeTrait[] typeTraits) {
+        super(typeTraits);
+    }
 
-	public int writeTupleFields(ITreeIndexTupleReference[] refs,
-			int startField, ByteBuffer targetBuf, int targetOff) {
-		int runner = targetOff;
-		int nullFlagsBytes = getNullFlagsBytes(refs.length);
-		// write null indicator bits
-		for (int i = 0; i < nullFlagsBytes; i++) {
-			targetBuf.put(runner++, (byte) 0);
-		}
+    public int writeTupleFields(ITreeIndexTupleReference[] refs, int startField, ByteBuffer targetBuf, int targetOff) {        
+    	int runner = targetOff;
+        int nullFlagsBytes = getNullFlagsBytes(refs.length);
+        // write null indicator bits
+        for (int i = 0; i < nullFlagsBytes; i++) {
+            targetBuf.put(runner++, (byte) 0);
+        }
 
-		// write field slots for variable length fields
-		// since the r-tree has fixed length keys, we don't actually need this?
-		encDec.reset(targetBuf.array(), runner);
-		for (int i = startField; i < startField + refs.length; i++) {
-			if (typeTraits[i].getStaticallyKnownDataLength() == ITypeTrait.VARIABLE_LENGTH) {
-				encDec.encode(refs[i].getFieldLength(i));
-			}
-		}
-		runner = encDec.getPos();
+        // write field slots for variable length fields
+        // since the r-tree has fixed length keys, we don't actually need this?
+        encDec.reset(targetBuf.array(), runner);
+        for (int i = startField; i < startField + refs.length; i++) {
+            if (typeTraits[i].getStaticallyKnownDataLength() == ITypeTrait.VARIABLE_LENGTH) {
+                encDec.encode(refs[i].getFieldLength(i));
+            }
+        }
+        runner = encDec.getPos();
 
-		// write data
-		for (int i = 0; i < refs.length; i++) {
-			System.arraycopy(refs[i].getFieldData(i), refs[i].getFieldStart(i),
-					targetBuf.array(), runner, refs[i].getFieldLength(i));
-			runner += refs[i].getFieldLength(i);
-		}
-		return runner - targetOff;
+        // write data
+        for (int i = 0; i < refs.length; i++) {
+            System.arraycopy(refs[i].getFieldData(i), refs[i].getFieldStart(i), targetBuf.array(), runner,
+                    refs[i].getFieldLength(i));
+            runner += refs[i].getFieldLength(i);
+        }
+        return runner - targetOff;
 
-	}
+    }
 }
diff --git a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/tuples/RTreeTypeAwareTupleWriterFactory.java b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/tuples/RTreeTypeAwareTupleWriterFactory.java
index 7d88f2e..a27d8cd 100644
--- a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/tuples/RTreeTypeAwareTupleWriterFactory.java
+++ b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/tuples/RTreeTypeAwareTupleWriterFactory.java
@@ -19,19 +19,17 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleWriter;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleWriterFactory;
 
-public class RTreeTypeAwareTupleWriterFactory implements
-		ITreeIndexTupleWriterFactory {
+public class RTreeTypeAwareTupleWriterFactory implements ITreeIndexTupleWriterFactory {
 
-	private static final long serialVersionUID = 1L;
-	private ITypeTrait[] typeTraits;
+    private static final long serialVersionUID = 1L;
+    private ITypeTrait[] typeTraits;
 
-	public RTreeTypeAwareTupleWriterFactory(ITypeTrait[] typeTraits) {
-		this.typeTraits = typeTraits;
-	}
+    public RTreeTypeAwareTupleWriterFactory(ITypeTrait[] typeTraits) {
+        this.typeTraits = typeTraits;
+    }
 
-	@Override
-	public ITreeIndexTupleWriter createTupleWriter() {
-		return new RTreeTypeAwareTupleWriter(typeTraits);
-	}
-
+    @Override    
+    public ITreeIndexTupleWriter createTupleWriter() {
+        return new RTreeTypeAwareTupleWriter(typeTraits);
+    }
 }
diff --git a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeFieldPrefixNSMTest.java b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeFieldPrefixNSMTest.java
index 4402e22..ab3d9d9 100644
--- a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeFieldPrefixNSMTest.java
+++ b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeFieldPrefixNSMTest.java
@@ -55,186 +55,171 @@
 
 public class BTreeFieldPrefixNSMTest extends AbstractBTreeTest {
 
-	private static final int PAGE_SIZE = 32768; // 32K
-	private static final int NUM_PAGES = 40;
-	private static final int MAX_OPEN_FILES = 10;
-	private static final int HYRACKS_FRAME_SIZE = 128;
-	private IHyracksTaskContext ctx = TestUtils.create(HYRACKS_FRAME_SIZE);
-		
-    private ITupleReference createTuple(IHyracksTaskContext ctx, int f0,
-			int f1, int f2, boolean print) throws HyracksDataException {
-		if (print)
-		    LOGGER.info("CREATING: " + f0 + " " + f1 + " " + f2);		
+    private static final int PAGE_SIZE = 32768; // 32K
+    private static final int NUM_PAGES = 40;
+    private static final int MAX_OPEN_FILES = 10;
+    private static final int HYRACKS_FRAME_SIZE = 128;
+    private IHyracksTaskContext ctx = TestUtils.create(HYRACKS_FRAME_SIZE);
 
-		ByteBuffer buf = ctx.allocateFrame();
-		FrameTupleAppender appender = new FrameTupleAppender(ctx.getFrameSize());
-		ArrayTupleBuilder tb = new ArrayTupleBuilder(3);
-		DataOutput dos = tb.getDataOutput();
+    private ITupleReference createTuple(IHyracksTaskContext ctx, int f0, int f1, int f2, boolean print)
+            throws HyracksDataException {
+        if (print)
+            LOGGER.info("CREATING: " + f0 + " " + f1 + " " + f2);
 
-		ISerializerDeserializer[] recDescSers = {
-				IntegerSerializerDeserializer.INSTANCE,
-				IntegerSerializerDeserializer.INSTANCE,
-				IntegerSerializerDeserializer.INSTANCE };
-		RecordDescriptor recDesc = new RecordDescriptor(recDescSers);
-		IFrameTupleAccessor accessor = new FrameTupleAccessor(ctx
-				.getFrameSize(), recDesc);
-		accessor.reset(buf);
-		FrameTupleReference tuple = new FrameTupleReference();
+        ByteBuffer buf = ctx.allocateFrame();
+        FrameTupleAppender appender = new FrameTupleAppender(ctx.getFrameSize());
+        ArrayTupleBuilder tb = new ArrayTupleBuilder(3);
+        DataOutput dos = tb.getDataOutput();
 
-		tb.reset();
-		IntegerSerializerDeserializer.INSTANCE.serialize(f0, dos);
-		tb.addFieldEndOffset();
-		IntegerSerializerDeserializer.INSTANCE.serialize(f1, dos);
-		tb.addFieldEndOffset();
-		IntegerSerializerDeserializer.INSTANCE.serialize(f2, dos);
-		tb.addFieldEndOffset();
+        ISerializerDeserializer[] recDescSers = { IntegerSerializerDeserializer.INSTANCE,
+                IntegerSerializerDeserializer.INSTANCE, IntegerSerializerDeserializer.INSTANCE };
+        RecordDescriptor recDesc = new RecordDescriptor(recDescSers);
+        IFrameTupleAccessor accessor = new FrameTupleAccessor(ctx.getFrameSize(), recDesc);
+        accessor.reset(buf);
+        FrameTupleReference tuple = new FrameTupleReference();
 
-		appender.reset(buf, true);
-		appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb
-				.getSize());
+        tb.reset();
+        IntegerSerializerDeserializer.INSTANCE.serialize(f0, dos);
+        tb.addFieldEndOffset();
+        IntegerSerializerDeserializer.INSTANCE.serialize(f1, dos);
+        tb.addFieldEndOffset();
+        IntegerSerializerDeserializer.INSTANCE.serialize(f2, dos);
+        tb.addFieldEndOffset();
 
-		tuple.reset(accessor, 0);
+        appender.reset(buf, true);
+        appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize());
 
-		return tuple;
-	}
+        tuple.reset(accessor, 0);
 
-	@Test
-	public void test01() throws Exception {
-		
-		TestStorageManagerComponentHolder.init(PAGE_SIZE, NUM_PAGES, MAX_OPEN_FILES);
-		IBufferCache bufferCache = TestStorageManagerComponentHolder
-				.getBufferCache(ctx);
-		IFileMapProvider fmp = TestStorageManagerComponentHolder
-				.getFileMapProvider(ctx);
-		FileReference file = new FileReference(new File(fileName));
-		bufferCache.createFile(file);
-		int fileId = fmp.lookupFileId(file);
-		bufferCache.openFile(fileId);
+        return tuple;
+    }
 
-		// declare fields
-		int fieldCount = 3;
-		ITypeTrait[] typeTraits = new ITypeTrait[fieldCount];
-		typeTraits[0] = new TypeTrait(4);
-		typeTraits[1] = new TypeTrait(4);
-		typeTraits[2] = new TypeTrait(4);
+    @Test
+    public void test01() throws Exception {
 
-		// declare keys
-		int keyFieldCount = 3;
-		IBinaryComparator[] cmps = new IBinaryComparator[keyFieldCount];
-		cmps[0] = IntegerBinaryComparatorFactory.INSTANCE
-				.createBinaryComparator();
-		cmps[1] = IntegerBinaryComparatorFactory.INSTANCE
-				.createBinaryComparator();
-		cmps[2] = IntegerBinaryComparatorFactory.INSTANCE
-				.createBinaryComparator();
-		MultiComparator cmp = new MultiComparator(typeTraits, cmps);
+        TestStorageManagerComponentHolder.init(PAGE_SIZE, NUM_PAGES, MAX_OPEN_FILES);
+        IBufferCache bufferCache = TestStorageManagerComponentHolder.getBufferCache(ctx);
+        IFileMapProvider fmp = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
+        FileReference file = new FileReference(new File(fileName));
+        bufferCache.createFile(file);
+        int fileId = fmp.lookupFileId(file);
+        bufferCache.openFile(fileId);
 
-		// just for printing
-		ISerializerDeserializer[] sers = {
-				IntegerSerializerDeserializer.INSTANCE,
-				IntegerSerializerDeserializer.INSTANCE,
-				IntegerSerializerDeserializer.INSTANCE };
+        // declare fields
+        int fieldCount = 3;
+        ITypeTrait[] typeTraits = new ITypeTrait[fieldCount];
+        typeTraits[0] = new TypeTrait(4);
+        typeTraits[1] = new TypeTrait(4);
+        typeTraits[2] = new TypeTrait(4);
 
-		Random rnd = new Random();
-		rnd.setSeed(50);
+        // declare keys
+        int keyFieldCount = 3;
+        IBinaryComparator[] cmps = new IBinaryComparator[keyFieldCount];
+        cmps[0] = IntegerBinaryComparatorFactory.INSTANCE.createBinaryComparator();
+        cmps[1] = IntegerBinaryComparatorFactory.INSTANCE.createBinaryComparator();
+        cmps[2] = IntegerBinaryComparatorFactory.INSTANCE.createBinaryComparator();
+        MultiComparator cmp = new MultiComparator(typeTraits, cmps);
 
-		ICachedPage page = bufferCache.pin(BufferedFileHandle.getDiskPageId(
-				fileId, 0), false);
-		try {
+        // just for printing
+        ISerializerDeserializer[] sers = { IntegerSerializerDeserializer.INSTANCE,
+                IntegerSerializerDeserializer.INSTANCE, IntegerSerializerDeserializer.INSTANCE };
 
-			IPrefixSlotManager slotManager = new FieldPrefixSlotManager();
-			ITreeIndexTupleWriter tupleWriter = new TypeAwareTupleWriter(typeTraits);
-			BTreeFieldPrefixNSMLeafFrame frame = new BTreeFieldPrefixNSMLeafFrame(
-					tupleWriter);
-			frame.setPage(page);
-			frame.initBuffer((byte) 0);
-			slotManager.setFrame(frame);
-			frame.setPrefixTupleCount(0);
+        Random rnd = new Random();
+        rnd.setSeed(50);
 
-			String before = new String();
-			String after = new String();
+        ICachedPage page = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, 0), false);
+        try {
 
-			int compactFreq = 5;
-			int compressFreq = 5;
-			int smallMax = 10;
-			int numRecords = 1000;
+            IPrefixSlotManager slotManager = new FieldPrefixSlotManager();
+            ITreeIndexTupleWriter tupleWriter = new TypeAwareTupleWriter(typeTraits);
+            BTreeFieldPrefixNSMLeafFrame frame = new BTreeFieldPrefixNSMLeafFrame(tupleWriter);
+            frame.setPage(page);
+            frame.initBuffer((byte) 0);
+            slotManager.setFrame(frame);
+            frame.setPrefixTupleCount(0);
 
-			int[][] savedFields = new int[numRecords][3];
+            String before = new String();
+            String after = new String();
 
-			// insert records with random calls to compact and compress
-			for (int i = 0; i < numRecords; i++) {
+            int compactFreq = 5;
+            int compressFreq = 5;
+            int smallMax = 10;
+            int numRecords = 1000;
 
-				if ((i + 1) % 100 == 0)
-					LOGGER.info("INSERTING " + (i + 1) + " / " + numRecords);
+            int[][] savedFields = new int[numRecords][3];
 
-				int a = rnd.nextInt() % smallMax;
-				int b = rnd.nextInt() % smallMax;
-				int c = i;
+            // insert records with random calls to compact and compress
+            for (int i = 0; i < numRecords; i++) {
 
-				ITupleReference tuple = createTuple(ctx, a, b, c, false);
-				try {
-					int targetTupleIndex = frame.findTupleIndex(tuple, cmp);
-					frame.insert(tuple, cmp, targetTupleIndex);
-				} catch (BTreeException e) {
-					e.printStackTrace();
-				} catch (Exception e) {
-					e.printStackTrace();
-				}
+                if ((i + 1) % 100 == 0)
+                    LOGGER.info("INSERTING " + (i + 1) + " / " + numRecords);
 
-				savedFields[i][0] = a;
-				savedFields[i][1] = b;
-				savedFields[i][2] = c;
+                int a = rnd.nextInt() % smallMax;
+                int b = rnd.nextInt() % smallMax;
+                int c = i;
+                
+                ITupleReference tuple = createTuple(ctx, a, b, c, false);
+                try {
+                    int targetTupleIndex = frame.findTupleIndex(tuple, cmp, true);
+                    frame.insert(tuple, cmp, targetTupleIndex);
+                } catch (BTreeException e) {
+                    e.printStackTrace();
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
 
-				if (rnd.nextInt() % compactFreq == 0) {
-					before = frame.printKeys(cmp, sers);
-					frame.compact(cmp);
-					after = frame.printKeys(cmp, sers);
-					Assert.assertEquals(before, after);
-				}
+                savedFields[i][0] = a;
+                savedFields[i][1] = b;
+                savedFields[i][2] = c;
 
-				if (rnd.nextInt() % compressFreq == 0) {
-					before = frame.printKeys(cmp, sers);
-					frame.compress(cmp);
-					after = frame.printKeys(cmp, sers);
-					Assert.assertEquals(before, after);
-				}
+                if (rnd.nextInt() % compactFreq == 0) {
+                    before = frame.printKeys(cmp, sers);                    
+                    frame.compact(cmp);
+                    after = frame.printKeys(cmp, sers);
+                    Assert.assertEquals(before, after);
+                }
 
-			}
+                if (rnd.nextInt() % compressFreq == 0) {
+                    before = frame.printKeys(cmp, sers);
+                    frame.compress(cmp);
+                    after = frame.printKeys(cmp, sers);
+                    Assert.assertEquals(before, after);
+                }
 
-			// delete records with random calls to compact and compress
-			for (int i = 0; i < numRecords; i++) {
+            }
 
-				if ((i + 1) % 100 == 0)
-					LOGGER.info("DELETING " + (i + 1) + " / " + numRecords);
+            // delete records with random calls to compact and compress
+            for (int i = 0; i < numRecords; i++) {
 
-				ITupleReference tuple = createTuple(ctx,
-						savedFields[i][0], savedFields[i][1],
-						savedFields[i][2], false);
-				try {
-					frame.delete(tuple, cmp, true);
-				} catch (Exception e) {
-				}
+                if ((i + 1) % 100 == 0)
+                    LOGGER.info("DELETING " + (i + 1) + " / " + numRecords);
 
-				if (rnd.nextInt() % compactFreq == 0) {
-					before = frame.printKeys(cmp, sers);
-					frame.compact(cmp);
-					after = frame.printKeys(cmp, sers);
-					Assert.assertEquals(before, after);
-				}
+                ITupleReference tuple = createTuple(ctx, savedFields[i][0], savedFields[i][1], savedFields[i][2], false);
+                try {
+                    frame.delete(tuple, cmp, true);
+                } catch (Exception e) {
+                }
 
-				if (rnd.nextInt() % compressFreq == 0) {
-					before = frame.printKeys(cmp, sers);
-					frame.compress(cmp);
-					after = frame.printKeys(cmp, sers);
-					Assert.assertEquals(before, after);
-				}
-			}
+                if (rnd.nextInt() % compactFreq == 0) {
+                    before = frame.printKeys(cmp, sers);
+                    frame.compact(cmp);
+                    after = frame.printKeys(cmp, sers);
+                    Assert.assertEquals(before, after);
+                }
 
-		} finally {
-			bufferCache.unpin(page);
-		}
+                if (rnd.nextInt() % compressFreq == 0) {
+                    before = frame.printKeys(cmp, sers);
+                    frame.compress(cmp);
+                    after = frame.printKeys(cmp, sers);
+                    Assert.assertEquals(before, after);
+                }
+            }
 
-		bufferCache.closeFile(fileId);
-		bufferCache.close();
-	}
+        } finally {
+            bufferCache.unpin(page);
+        }
+
+        bufferCache.closeFile(fileId);
+        bufferCache.close();
+    }
 }
diff --git a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeTest.java b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeTest.java
index a9debd5..4c7e429 100644
--- a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeTest.java
+++ b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeTest.java
@@ -15,9 +15,13 @@
 
 package edu.uci.ics.hyracks.storage.am.btree;
 
+import java.io.ByteArrayInputStream;
+import java.io.DataInputStream;
 import java.io.DataOutput;
 import java.io.File;
 import java.nio.ByteBuffer;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Random;
 
 import org.junit.Test;
@@ -29,6 +33,7 @@
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.value.TypeTrait;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
@@ -107,7 +112,7 @@
         MultiComparator cmp = new MultiComparator(typeTraits, cmps);
 
         TypeAwareTupleWriterFactory tupleWriterFactory = new TypeAwareTupleWriterFactory(typeTraits);
-        ITreeIndexFrameFactory leafFrameFactory = new BTreeNSMLeafFrameFactory(tupleWriterFactory);
+        ITreeIndexFrameFactory leafFrameFactory = new BTreeNSMLeafFrameFactory(tupleWriterFactory);        
         ITreeIndexFrameFactory interiorFrameFactory = new BTreeNSMInteriorFrameFactory(tupleWriterFactory);
         ITreeIndexMetaDataFrameFactory metaFrameFactory = new LIFOMetaDataFrameFactory();
 
@@ -313,9 +318,8 @@
         MultiComparator cmp = new MultiComparator(typeTraits, cmps);
 
         TypeAwareTupleWriterFactory tupleWriterFactory = new TypeAwareTupleWriterFactory(typeTraits);
-        // SimpleTupleWriterFactory tupleWriterFactory = new
-        // SimpleTupleWriterFactory();
         ITreeIndexFrameFactory leafFrameFactory = new BTreeNSMLeafFrameFactory(tupleWriterFactory);
+        //ITreeIndexFrameFactory leafFrameFactory = new BTreeFieldPrefixNSMLeafFrameFactory(tupleWriterFactory);
         ITreeIndexFrameFactory interiorFrameFactory = new BTreeNSMInteriorFrameFactory(tupleWriterFactory);
         ITreeIndexMetaDataFrameFactory metaFrameFactory = new LIFOMetaDataFrameFactory();
 
@@ -499,9 +503,7 @@
 
         MultiComparator cmp = new MultiComparator(typeTraits, cmps);
 
-        SimpleTupleWriterFactory tupleWriterFactory = new SimpleTupleWriterFactory();
-        // TypeAwareTupleWriterFactory tupleWriterFactory = new
-        // TypeAwareTupleWriterFactory(typeTraits);
+        TypeAwareTupleWriterFactory tupleWriterFactory = new TypeAwareTupleWriterFactory(typeTraits);
         ITreeIndexFrameFactory leafFrameFactory = new BTreeNSMLeafFrameFactory(tupleWriterFactory);
         ITreeIndexFrameFactory interiorFrameFactory = new BTreeNSMInteriorFrameFactory(tupleWriterFactory);
         ITreeIndexMetaDataFrameFactory metaFrameFactory = new LIFOMetaDataFrameFactory();
@@ -674,8 +676,6 @@
 
         MultiComparator cmp = new MultiComparator(typeTraits, cmps);
 
-        // SimpleTupleWriterFactory tupleWriterFactory = new
-        // SimpleTupleWriterFactory();
         TypeAwareTupleWriterFactory tupleWriterFactory = new TypeAwareTupleWriterFactory(typeTraits);
         ITreeIndexFrameFactory leafFrameFactory = new BTreeNSMLeafFrameFactory(tupleWriterFactory);
         ITreeIndexFrameFactory interiorFrameFactory = new BTreeNSMInteriorFrameFactory(tupleWriterFactory);
@@ -804,12 +804,216 @@
         bufferCache.close();
     }
 
+    
+    private void orderedScan(BTree btree, IBTreeLeafFrame leafFrame, IBTreeInteriorFrame interiorFrame, ISerializerDeserializer[] recDescSers) throws Exception {
+        // try a simple index scan
+        LOGGER.info("ORDERED SCAN:");
+        ITreeIndexCursor scanCursor = new BTreeRangeSearchCursor(leafFrame);
+        RangePredicate nullPred = new RangePredicate(true, null, null, true, true, null, null);
+        BTreeOpContext searchOpCtx = btree.createOpContext(IndexOp.SEARCH, leafFrame, interiorFrame, null);
+        btree.search(scanCursor, nullPred, searchOpCtx);
+        StringBuilder scanResults = new StringBuilder();
+        try {
+            while (scanCursor.hasNext()) {
+                scanCursor.next();
+                ITupleReference frameTuple = scanCursor.getTuple();
+                String rec = btree.getMultiComparator().printTuple(frameTuple, recDescSers);
+                scanResults.append("\n" + rec);
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            scanCursor.close();
+        }
+        LOGGER.info(scanResults.toString());
+    }
+    
+    // Assuming exactly two BTree fields.
+    private void compareActualAndExpected(ITreeIndexCursor actualCursor, Map<String, String> expectedValues, ISerializerDeserializer[] fieldSerdes) throws Exception {
+        while (actualCursor.hasNext()) {
+            actualCursor.next();
+            ITupleReference tuple = actualCursor.getTuple();
+            String f0 = (String) deserializeField(tuple, 0, fieldSerdes[0]);
+            String f1 = (String) deserializeField(tuple, 1, fieldSerdes[1]);
+            String expected = expectedValues.get(f0);
+            if (!expected.equals(f1)) {
+                throw new Exception("FAILED: " + f0 + " " + f1 + " " + expected);
+            }
+        }
+    }
+    
+    private Object deserializeField(ITupleReference tuple, int fIdx, ISerializerDeserializer serde) throws HyracksDataException {
+        DataInputStream in = new DataInputStream(new ByteArrayInputStream(tuple.getFieldData(fIdx), tuple.getFieldStart(fIdx), tuple.getFieldLength(fIdx)));
+        return serde.deserialize(in);
+    }
+    
+    // UPDATE TEST
+    // create a B-tree with one variable-length "key" field and one
+    // variable-length "value" field
+    // fill B-tree with random values using insertions, then update entries
+    // one-by-one
+    // repeat procedure a few times on same B-tree
+    @Test
+    public void test05() throws Exception {
+
+        LOGGER.info("DELETION TEST");
+
+        TestStorageManagerComponentHolder.init(PAGE_SIZE, NUM_PAGES, MAX_OPEN_FILES);
+        IBufferCache bufferCache = TestStorageManagerComponentHolder.getBufferCache(ctx);
+        IFileMapProvider fmp = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
+        FileReference file = new FileReference(new File(fileName));
+        bufferCache.createFile(file);
+        int fileId = fmp.lookupFileId(file);
+        bufferCache.openFile(fileId);
+
+        // declare fields
+        int fieldCount = 2;
+        ITypeTrait[] typeTraits = new ITypeTrait[fieldCount];
+        typeTraits[0] = new TypeTrait(ITypeTrait.VARIABLE_LENGTH);
+        typeTraits[1] = new TypeTrait(ITypeTrait.VARIABLE_LENGTH);
+
+        // declare keys
+        int keyFieldCount = 1;
+        IBinaryComparator[] cmps = new IBinaryComparator[keyFieldCount];
+        cmps[0] = UTF8StringBinaryComparatorFactory.INSTANCE.createBinaryComparator();
+
+        MultiComparator cmp = new MultiComparator(typeTraits, cmps);
+
+        //TypeAwareTupleWriterFactory tupleWriterFactory = new TypeAwareTupleWriterFactory(typeTraits);
+        SimpleTupleWriterFactory tupleWriterFactory = new SimpleTupleWriterFactory();
+        ITreeIndexFrameFactory leafFrameFactory = new BTreeNSMLeafFrameFactory(tupleWriterFactory);
+        ITreeIndexFrameFactory interiorFrameFactory = new BTreeNSMInteriorFrameFactory(tupleWriterFactory);
+        ITreeIndexMetaDataFrameFactory metaFrameFactory = new LIFOMetaDataFrameFactory();
+
+        IBTreeLeafFrame leafFrame = (IBTreeLeafFrame) leafFrameFactory.createFrame();
+        IBTreeInteriorFrame interiorFrame = (IBTreeInteriorFrame) interiorFrameFactory.createFrame();
+        ITreeIndexMetaDataFrame metaFrame = metaFrameFactory.createFrame();
+
+        IFreePageManager freePageManager = new LinkedListFreePageManager(bufferCache, fileId, 0, metaFrameFactory);
+
+        BTree btree = new BTree(bufferCache, freePageManager, interiorFrameFactory, leafFrameFactory, cmp);
+        btree.create(fileId, leafFrame, metaFrame);
+        btree.open(fileId);
+
+        Random rnd = new Random();
+        rnd.setSeed(50);
+
+        ByteBuffer frame = ctx.allocateFrame();
+        FrameTupleAppender appender = new FrameTupleAppender(ctx.getFrameSize());
+        ArrayTupleBuilder tb = new ArrayTupleBuilder(cmp.getFieldCount());
+        DataOutput dos = tb.getDataOutput();
+
+        ISerializerDeserializer[] fieldSerdes = { UTF8StringSerializerDeserializer.INSTANCE,
+                UTF8StringSerializerDeserializer.INSTANCE };
+        RecordDescriptor recDesc = new RecordDescriptor(fieldSerdes);
+        IFrameTupleAccessor accessor = new FrameTupleAccessor(ctx.getFrameSize(), recDesc);
+        accessor.reset(frame);
+        FrameTupleReference tuple = new FrameTupleReference();
+
+        BTreeOpContext insertOpCtx = btree.createOpContext(IndexOp.INSERT, leafFrame, interiorFrame, metaFrame);
+        BTreeOpContext updateOpCtx = btree.createOpContext(IndexOp.UPDATE, leafFrame, interiorFrame, metaFrame);
+
+        Map<String, String> expectedValues = new HashMap<String, String>();
+        
+        LOGGER.info("INSERTING INTO BTREE");
+        int maxLength = 10;
+        int ins = 10000;
+        // Only remember the keys.
+        String[] f0s = new String[ins];
+        for (int i = 0; i < ins; i++) {
+            String f0 = randomString(Math.abs(rnd.nextInt()) % maxLength + 1, rnd);
+            String f1 = randomString(Math.abs(rnd.nextInt()) % maxLength + 1, rnd);
+
+            f0s[i] = f0;
+
+            tb.reset();
+            UTF8StringSerializerDeserializer.INSTANCE.serialize(f0, dos);
+            tb.addFieldEndOffset();
+            UTF8StringSerializerDeserializer.INSTANCE.serialize(f1, dos);
+            tb.addFieldEndOffset();
+
+            appender.reset(frame, true);
+            appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize());
+
+            tuple.reset(accessor, 0);
+
+            if (i % 1000 == 0) {
+                LOGGER.info("INSERTING " + i);
+            }
+            try {
+                btree.insert(tuple, insertOpCtx);
+                expectedValues.put(f0, f1);
+            } catch (TreeIndexException e) {
+                // e.printStackTrace();
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+        ITreeIndexCursor insertCheckCursor = new BTreeRangeSearchCursor(leafFrame);
+        RangePredicate nullPred = new RangePredicate(true, null, null, true, true, null, null);
+        BTreeOpContext searchOpCtx = btree.createOpContext(IndexOp.SEARCH, leafFrame, interiorFrame, null);
+        btree.search(insertCheckCursor, nullPred, searchOpCtx);
+        try {
+            compareActualAndExpected(insertCheckCursor, expectedValues, fieldSerdes);
+        } finally {
+            insertCheckCursor.close();
+        }
+        
+        int runs = 3;
+        for (int run = 0; run < runs; run++) {
+
+            LOGGER.info("UPDATE TEST RUN: " + (run + 1) + "/" + runs);
+
+            LOGGER.info("UPDATING BTREE");
+            for (int i = 0; i < ins; i++) {
+                // Generate a new random value for f1.
+                String f1 = randomString(Math.abs(rnd.nextInt()) % maxLength + 1, rnd);
+                
+                tb.reset();
+                UTF8StringSerializerDeserializer.INSTANCE.serialize(f0s[i], dos);
+                tb.addFieldEndOffset();
+                UTF8StringSerializerDeserializer.INSTANCE.serialize(f1, dos);
+                tb.addFieldEndOffset();
+
+                appender.reset(frame, true);
+                appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize());
+
+                tuple.reset(accessor, 0);
+
+                if (i % 1000 == 0) {
+                    LOGGER.info("UPDATING " + i);
+                }
+
+                try {
+                    btree.update(tuple, updateOpCtx);
+                    expectedValues.put(f0s[i], f1);
+                } catch (TreeIndexException e) {
+                    e.printStackTrace();
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+            }
+            
+            ITreeIndexCursor updateCheckCursor = new BTreeRangeSearchCursor(leafFrame);
+            btree.search(updateCheckCursor, nullPred, searchOpCtx);
+            try {
+                compareActualAndExpected(updateCheckCursor, expectedValues, fieldSerdes);
+            } finally {
+                updateCheckCursor.close();
+            }
+        }
+
+        btree.close();
+        bufferCache.closeFile(fileId);
+        bufferCache.close();
+    }
+    
     // BULK LOAD TEST
     // insert 100,000 records in bulk
     // B-tree has a composite key to "simulate" non-unique index creation
     // do range search
     @Test
-    public void test05() throws Exception {
+    public void test06() throws Exception {
 
         LOGGER.info("BULK LOAD TEST");
 
@@ -836,8 +1040,6 @@
 
         MultiComparator cmp = new MultiComparator(typeTraits, cmps);
 
-        // SimpleTupleWriterFactory tupleWriterFactory = new
-        // SimpleTupleWriterFactory();
         TypeAwareTupleWriterFactory tupleWriterFactory = new TypeAwareTupleWriterFactory(typeTraits);
         ITreeIndexFrameFactory leafFrameFactory = new BTreeNSMLeafFrameFactory(tupleWriterFactory);
         ITreeIndexFrameFactory interiorFrameFactory = new BTreeNSMInteriorFrameFactory(tupleWriterFactory);
@@ -965,7 +1167,7 @@
     // demo for Arjun to show easy support of intersection queries on
     // time-intervals
     @Test
-    public void test06() throws Exception {
+    public void test07() throws Exception {
 
         LOGGER.info("TIME-INTERVAL INTERSECTION DEMO");
 
@@ -991,8 +1193,6 @@
         cmps[1] = IntegerBinaryComparatorFactory.INSTANCE.createBinaryComparator();
         MultiComparator cmp = new MultiComparator(typeTraits, cmps);
 
-        // SimpleTupleWriterFactory tupleWriterFactory = new
-        // SimpleTupleWriterFactory();
         TypeAwareTupleWriterFactory tupleWriterFactory = new TypeAwareTupleWriterFactory(typeTraits);
         ITreeIndexFrameFactory leafFrameFactory = new BTreeNSMLeafFrameFactory(tupleWriterFactory);
         ITreeIndexFrameFactory interiorFrameFactory = new BTreeNSMInteriorFrameFactory(tupleWriterFactory);