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 07a52be..5fce2a1 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
@@ -141,7 +141,7 @@
         // due to ongoing structure modifications during the descent
         boolean repeatOp = true;
         while (repeatOp && ctx.opRestarts < MAX_RESTARTS) {
-            performOp(rootPage, null, ctx);
+            performOp(rootPage, null, true, 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) {
@@ -232,7 +232,7 @@
         // due to ongoing structure modifications during the descent.
         boolean repeatOp = true;
         while (repeatOp && ctx.opRestarts < MAX_RESTARTS) {
-            performOp(rootPage, null, ctx);
+            performOp(rootPage, null, true, ctx);
             // 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
@@ -469,19 +469,13 @@
         return false;
     }
 
-    private final void acquireLatch(ICachedPage node, BTreeOpContext ctx, boolean isLeaf) {
+    private final boolean acquireLatch(ICachedPage node, BTreeOpContext ctx, boolean isLeaf) {
         if (!isLeaf || (ctx.op == IndexOp.SEARCH && !ctx.cursor.exclusiveLatchNodes())) {
             node.acquireReadLatch();
+            return true;
         } else {
             node.acquireWriteLatch();
-        }
-    }
-
-    private final void releaseLatch(ICachedPage node, BTreeOpContext ctx, boolean isLeaf) {
-        if (!isLeaf || (ctx.op == IndexOp.SEARCH && !ctx.cursor.exclusiveLatchNodes())) {
-            node.releaseReadLatch();
-        } else {
-            node.releaseWriteLatch();
+            return false;
         }
     }
 
@@ -499,14 +493,14 @@
         return isConsistent;
     }
 
-    private void performOp(int pageId, ICachedPage parent, BTreeOpContext ctx) throws HyracksDataException, TreeIndexException {
+    private void performOp(int pageId, ICachedPage parent, boolean parentIsReadLatched, BTreeOpContext ctx) throws HyracksDataException, TreeIndexException {
         ICachedPage node = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, pageId), false);
         ctx.interiorFrame.setPage(node);
         
         // this check performs an unprotected read in the page
         // the following could happen: TODO fill out
         boolean unsafeIsLeaf = ctx.interiorFrame.isLeaf();
-        acquireLatch(node, ctx, unsafeIsLeaf);
+        boolean isReadLatched = acquireLatch(node, ctx, unsafeIsLeaf);
         boolean smFlag = ctx.interiorFrame.getSmFlag();
         // re-check leafness after latching
         boolean isLeaf = ctx.interiorFrame.isLeaf();
@@ -515,10 +509,13 @@
         // structure modification
         ctx.pageLsns.add(ctx.interiorFrame.getPageLsn());
         try {
-            // latch coupling, note: parent should never be write latched,
-            // otherwise something is wrong.
+            // Latch coupling: unlatch parent.
             if (parent != null) {
-                parent.releaseReadLatch();
+                if (parentIsReadLatched) {
+                	parent.releaseReadLatch();
+                } else {
+                	parent.releaseWriteLatch();
+                }
                 bufferCache.unpin(parent);
             }
             if (!isLeaf || smFlag) {
@@ -529,7 +526,7 @@
                     boolean repeatOp = true;
                     while (repeatOp && ctx.opRestarts < MAX_RESTARTS) {
                         int childPageId = ctx.interiorFrame.getChildPageId(ctx.pred);
-                        performOp(childPageId, node, ctx);
+                        performOp(childPageId, node, isReadLatched, ctx);
 
                         if (!ctx.pageLsns.isEmpty() && ctx.pageLsns.getLast() == RESTART_OP) {
                             // Pop the restart op indicator.
@@ -539,6 +536,7 @@
                                 node = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, pageId), false);
                                 node.acquireReadLatch();
                                 ctx.interiorFrame.setPage(node);
+                                isReadLatched = true;
                                 // Descend the tree again.                                
                                 continue;
                             } else {
@@ -587,7 +585,11 @@
                     } // end while
                 } else { // smFlag
                     ctx.opRestarts++;
-                    releaseLatch(node, ctx, unsafeIsLeaf);
+                    if (isReadLatched) {
+                    	node.releaseReadLatch();
+                    } else {
+                    	node.releaseWriteLatch();
+                    }
                     bufferCache.unpin(node);
 
                     // TODO: this should be an instant duration lock, how to do
@@ -635,7 +637,11 @@
         } catch (TreeIndexException e) {
         	if (!ctx.exceptionHandled) {
         		if (node != null) {
-        			releaseLatch(node, ctx, unsafeIsLeaf);
+        			if (isReadLatched) {
+        				node.releaseReadLatch();
+        			} else {
+        				node.releaseWriteLatch();
+        			}
         			bufferCache.unpin(node);
         			ctx.exceptionHandled = true;
         		}
@@ -644,7 +650,11 @@
         } catch (Exception e) {
         	e.printStackTrace();
         	if (node != null) {
-        		releaseLatch(node, ctx, unsafeIsLeaf);
+        		if (isReadLatched) {
+    				node.releaseReadLatch();
+    			} else {
+    				node.releaseWriteLatch();
+    			}
         		bufferCache.unpin(node);
         	}
             BTreeException wrappedException = new BTreeException(e);
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/tests/OrderedIndexMultiThreadTest.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/tests/OrderedIndexMultiThreadTest.java
new file mode 100644
index 0000000..f7beb65
--- /dev/null
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/tests/OrderedIndexMultiThreadTest.java
@@ -0,0 +1,125 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.btree.tests;
+
+import java.util.ArrayList;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import org.junit.Test;
+
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
+import edu.uci.ics.hyracks.dataflow.common.data.marshalling.UTF8StringSerializerDeserializer;
+import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+import edu.uci.ics.hyracks.storage.am.common.test.ITreeIndexTestWorkerFactory;
+import edu.uci.ics.hyracks.storage.am.common.test.TestOperationSelector.TestOperation;
+import edu.uci.ics.hyracks.storage.am.common.test.TestWorkloadConf;
+import edu.uci.ics.hyracks.storage.am.common.test.TreeIndexMultiThreadTestDriver;
+
+@SuppressWarnings("rawtypes")
+public abstract class OrderedIndexMultiThreadTest {    
+    
+    protected final Logger LOGGER = Logger.getLogger(OrderedIndexMultiThreadTest.class.getName());
+    
+    // Machine-specific number of threads to use for testing.
+    protected final int REGULAR_NUM_THREADS = Runtime.getRuntime().availableProcessors();
+    // Excessive number of threads for testing.
+    protected final int EXCESSIVE_NUM_THREADS = Runtime.getRuntime().availableProcessors() * 4;
+    protected final int NUM_OPERATIONS = 10000;
+    
+    protected ArrayList<TestWorkloadConf> workloadConfs = getTestWorkloadConf();    
+    
+    protected abstract void setUp() throws HyracksDataException;
+    
+    protected abstract void tearDown() throws HyracksDataException;        
+
+    protected abstract ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories) throws TreeIndexException;
+    
+    protected abstract int getFileId();
+    
+    protected abstract ITreeIndexTestWorkerFactory getWorkerFactory();
+    
+    protected abstract ArrayList<TestWorkloadConf> getTestWorkloadConf();
+    
+    protected abstract String getIndexTypeName();
+    
+    protected static float[] getUniformOpProbs(TestOperation[] ops) {
+        float[] opProbs = new float[ops.length];
+        for (int i = 0; i < ops.length; i++) {
+            opProbs[i] = 1.0f / (float) ops.length;
+        }
+        return opProbs;
+    }
+    
+    protected void runTest(ISerializerDeserializer[] fieldSerdes, int numKeys, int numThreads, TestWorkloadConf conf, String dataMsg) throws HyracksDataException, InterruptedException, TreeIndexException {
+        setUp();
+        
+        if (LOGGER.isLoggable(Level.INFO)) {
+        	String indexTypeName = getIndexTypeName();
+            LOGGER.info(indexTypeName + " MultiThread Test:\nData: " + dataMsg + "; Threads: " + numThreads + "; Workload: " + conf.toString() + ".");
+        }
+        
+        ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
+        IBinaryComparatorFactory[] cmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes, numKeys);     
+        
+        ITreeIndex index = createTreeIndex(typeTraits, cmpFactories);
+        ITreeIndexTestWorkerFactory workerFactory = getWorkerFactory();
+        
+        // 4 batches per thread.
+        int batchSize = (NUM_OPERATIONS / numThreads) / 4;
+        
+        TreeIndexMultiThreadTestDriver driver = new TreeIndexMultiThreadTestDriver(index, workerFactory, fieldSerdes, conf.ops, conf.opProbs);
+        driver.init(getFileId());
+        long[] times = driver.run(numThreads, 1, NUM_OPERATIONS, batchSize);
+        driver.deinit();
+        
+        if (LOGGER.isLoggable(Level.INFO)) {
+            LOGGER.info("BTree MultiThread Test Time: " + times[0] + "ms");
+        }
+        
+        tearDown();
+    }
+    
+    @Test
+    public void oneIntKeyAndValue() throws InterruptedException, HyracksDataException, TreeIndexException {        
+        ISerializerDeserializer[] fieldSerdes = new ISerializerDeserializer[] { IntegerSerializerDeserializer.INSTANCE, IntegerSerializerDeserializer.INSTANCE };
+        int numKeys = 1;
+        String dataMsg = "One Int Key And Value";
+        
+        for (TestWorkloadConf conf : workloadConfs) {
+            runTest(fieldSerdes, numKeys, REGULAR_NUM_THREADS, conf, dataMsg);
+            runTest(fieldSerdes, numKeys, EXCESSIVE_NUM_THREADS, conf, dataMsg);
+        }
+    }
+    
+    @Test
+    public void oneStringKeyAndValue() throws InterruptedException, HyracksDataException, TreeIndexException {        
+        ISerializerDeserializer[] fieldSerdes = new ISerializerDeserializer[] { UTF8StringSerializerDeserializer.INSTANCE, UTF8StringSerializerDeserializer.INSTANCE };
+        int numKeys = 1;
+        String dataMsg = "One String Key And Value";
+        
+        for (TestWorkloadConf conf : workloadConfs) {
+            runTest(fieldSerdes, numKeys, REGULAR_NUM_THREADS, conf, dataMsg);
+            runTest(fieldSerdes, numKeys, EXCESSIVE_NUM_THREADS, conf, dataMsg);
+        }
+    }
+}
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/test/TestOperationSelector.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/test/TestOperationSelector.java
index 25058a9..efc1ec4 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/test/TestOperationSelector.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/test/TestOperationSelector.java
@@ -27,7 +27,6 @@
         RANGE_SEARCH,
         ORDERED_SCAN,
         DISKORDER_SCAN,
-        FLUSH,
         MERGE        
     }
     
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
index cfa3ba3..fa25083 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
@@ -44,6 +44,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IndexType;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOp;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFileNameManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMTree;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
@@ -497,7 +498,7 @@
         return new LSMBTreeIndexAccessor(lsmHarness, createOpContext());
     }
     
-    private class LSMBTreeIndexAccessor extends LSMTreeIndexAccessor {
+    public class LSMBTreeIndexAccessor extends LSMTreeIndexAccessor {
         public LSMBTreeIndexAccessor(LSMHarness lsmHarness, IIndexOpContext ctx) {
             super(lsmHarness, ctx);
         }
@@ -506,5 +507,10 @@
         public ITreeIndexCursor createSearchCursor() {
             return new LSMBTreeRangeSearchCursor();
         }
+        
+        public MultiComparator getMultiComparator() {
+            LSMBTreeOpContext concreteCtx = (LSMBTreeOpContext) ctx;
+            return concreteCtx.cmp;
+        }
     }
 }
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeRangeSearchCursor.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeRangeSearchCursor.java
index 46f563f..6f45287 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeRangeSearchCursor.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeRangeSearchCursor.java
@@ -48,8 +48,9 @@
     }
 
     public void initPriorityQueue()
-            throws HyracksDataException {                
-        outputPriorityQueue = new PriorityQueue<PriorityQueueElement>(rangeCursors.length, pqCmp);
+            throws HyracksDataException {
+        int pqInitSize = (rangeCursors.length > 0) ? rangeCursors.length : 1;
+        outputPriorityQueue = new PriorityQueue<PriorityQueueElement>(pqInitSize, pqCmp);
         for (int i = 0; i < rangeCursors.length; i++) {
             PriorityQueueElement element;
             if (rangeCursors[i].hasNext()) {
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMTreeIndexAccessor.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMTreeIndexAccessor.java
index 0289dd6..032b112 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMTreeIndexAccessor.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMTreeIndexAccessor.java
@@ -35,11 +35,11 @@
 	 */
 	public void flush() throws HyracksDataException, TreeIndexException;
 
-	/**
-	 * Merge all on-disk components.
-	 * 
-	 * @throws HyracksDataException
-	 * @throws TreeIndexException
-	 */
-	public void merge() throws HyracksDataException, TreeIndexException;
+    /**
+     * Merge all on-disk components.
+     * 
+     * @throws HyracksDataException
+     * @throws TreeIndexException
+     */
+    public void merge() throws HyracksDataException, TreeIndexException;
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
index 3ca0d41..aab1137 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
@@ -157,12 +157,13 @@
     }
 
     public void merge() throws HyracksDataException, TreeIndexException  {
+        if (!isMerging.compareAndSet(false, true)) {
+            throw new LSMMergeInProgressException("Merge already in progress in LSMTree. Only one concurrent merge allowed.");
+        }
+        
         if (LOGGER.isLoggable(Level.INFO)) {
             LOGGER.info("Merging LSM-Tree.");
         }
-        if (!isMerging.compareAndSet(false, true)) {
-            throw new TreeIndexException("Merge already in progress in LSMTree. Only one concurrent merge allowed.");
-        }
         
         // Point to the current searcher ref count, so we can wait for it later
         // (after we swap the searcher ref count).
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMMergeInProgressException.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMMergeInProgressException.java
new file mode 100644
index 0000000..9834fae
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMMergeInProgressException.java
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+
+public class LSMMergeInProgressException extends TreeIndexException {
+
+    private static final long serialVersionUID = 1L;
+    
+    public LSMMergeInProgressException(Exception e) {        
+        super(e);
+    }
+
+    public LSMMergeInProgressException(String message) {
+        super(message);
+    }
+
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java
index 6d9cba3..98cfce7 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java
@@ -10,8 +10,8 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMTreeIndexAccessor;
 
 public abstract class LSMTreeIndexAccessor implements ILSMTreeIndexAccessor {
-	private LSMHarness lsmHarness;
-	private IIndexOpContext ctx;
+	protected LSMHarness lsmHarness;
+	protected IIndexOpContext ctx;
 
 	public LSMTreeIndexAccessor(LSMHarness lsmHarness, IIndexOpContext ctx) {
 		this.lsmHarness = lsmHarness;
diff --git a/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/BufferCache.java b/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/BufferCache.java
index 1d2b091..f213ee6 100644
--- a/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/BufferCache.java
+++ b/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/BufferCache.java
@@ -135,8 +135,8 @@
 
         CachedPage cPage = findPage(dpid, newPage);
         if (cPage == null) {
-            if (LOGGER.isLoggable(Level.INFO)) {
-                LOGGER.info(dumpState());
+            if (LOGGER.isLoggable(Level.FINE)) {
+                LOGGER.fine(dumpState());
             }
             throw new HyracksDataException("Failed to pin page " + BufferedFileHandle.getFileId(dpid) + ":"
                     + BufferedFileHandle.getPageId(dpid) + " because all pages are pinned.");
@@ -703,8 +703,11 @@
     public void closeFile(int fileId) throws HyracksDataException {
         if (LOGGER.isLoggable(Level.INFO)) {
             LOGGER.info("Closing file: " + fileId + " in cache: " + this);
-            LOGGER.info(dumpState());
         }
+        if (LOGGER.isLoggable(Level.FINE)) {            
+            LOGGER.fine(dumpState());
+        }
+        
         synchronized (fileInfoMap) {
             BufferedFileHandle fInfo = fileInfoMap.get(fileId);
             if (fInfo == null) {
diff --git a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeMultiThreadTest.java
index 394e512..2dea763 100644
--- a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeMultiThreadTest.java
+++ b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeMultiThreadTest.java
@@ -16,44 +16,48 @@
 package edu.uci.ics.hyracks.storage.am.btree.multithread;
 
 import java.util.ArrayList;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import org.junit.Test;
 
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
-import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
-import edu.uci.ics.hyracks.dataflow.common.data.marshalling.UTF8StringSerializerDeserializer;
-import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
-import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
+import edu.uci.ics.hyracks.storage.am.btree.tests.OrderedIndexMultiThreadTest;
 import edu.uci.ics.hyracks.storage.am.btree.util.BTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.btree.util.BTreeUtils;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+import edu.uci.ics.hyracks.storage.am.common.test.ITreeIndexTestWorkerFactory;
 import edu.uci.ics.hyracks.storage.am.common.test.TestOperationSelector.TestOperation;
 import edu.uci.ics.hyracks.storage.am.common.test.TestWorkloadConf;
-import edu.uci.ics.hyracks.storage.am.common.test.TreeIndexMultiThreadTestDriver;
 
-@SuppressWarnings("rawtypes")
-public class BTreeMultiThreadTest {    
-    
-    protected final Logger LOGGER = Logger.getLogger(BTreeMultiThreadTest.class.getName());
-    
-    private final BTreeTestWorkerFactory workerFactory = new BTreeTestWorkerFactory();
-    private final BTreeTestHarness harness = new BTreeTestHarness();
+public class BTreeMultiThreadTest extends OrderedIndexMultiThreadTest {
 
-    // Machine-specific number of threads to use for testing.
-    private final int REGULAR_NUM_THREADS = Runtime.getRuntime().availableProcessors();
-    // Excessive number of threads for testing.
-    private final int EXCESSIVE_NUM_THREADS = Runtime.getRuntime().availableProcessors() * 4;
-    private final int NUM_OPERATIONS = 20000;
+    private BTreeTestHarness harness = new BTreeTestHarness();
     
-    private ArrayList<TestWorkloadConf> workloadConfs = getTestWorkloadConf();
+    private BTreeTestWorkerFactory workerFactory = new BTreeTestWorkerFactory();
+    
+    @Override
+    protected void setUp() throws HyracksDataException {
+        harness.setUp();
+    }
 
-    private static ArrayList<TestWorkloadConf> getTestWorkloadConf() {
+    @Override
+    protected void tearDown() throws HyracksDataException {
+        harness.tearDown();
+    }
+
+    @Override
+    protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories) throws TreeIndexException {
+        return BTreeUtils.createBTree(harness.getBufferCache(), harness.getBTreeFileId(), typeTraits, cmpFactories, BTreeLeafFrameType.REGULAR_NSM);
+    }
+
+    @Override
+    protected ITreeIndexTestWorkerFactory getWorkerFactory() {
+        return workerFactory;
+    }
+
+    @Override
+    protected ArrayList<TestWorkloadConf> getTestWorkloadConf() {
         ArrayList<TestWorkloadConf> workloadConfs = new ArrayList<TestWorkloadConf>();
         
         // Insert only workload.
@@ -74,64 +78,14 @@
         
         return workloadConfs;
     }
-    
-    private static float[] getUniformOpProbs(TestOperation[] ops) {
-        float[] opProbs = new float[ops.length];
-        for (int i = 0; i < ops.length; i++) {
-            opProbs[i] = 1.0f / (float) ops.length;
-        }
-        return opProbs;
+
+    @Override
+    protected int getFileId() {
+        return harness.getBTreeFileId();
     }
-    
-    private void runTest(ISerializerDeserializer[] fieldSerdes, int numKeys, int numThreads, TestWorkloadConf conf, String dataMsg) throws HyracksDataException, InterruptedException, TreeIndexException {
-        harness.setUp();
-        
-        if (LOGGER.isLoggable(Level.INFO)) {
-            LOGGER.info("BTree MultiThread Test:\nData: " + dataMsg + "; Threads: " + numThreads + "; Workload: " + conf.toString() + ".");
-        }
-        
-        ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
-        IBinaryComparatorFactory[] cmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes, numKeys);     
-        
-        BTree btree = BTreeUtils.createBTree(harness.getBufferCache(), harness.getBTreeFileId(), typeTraits, cmpFactories, BTreeLeafFrameType.REGULAR_NSM);
-        
-        // 4 batches per thread.
-        int batchSize = (NUM_OPERATIONS / numThreads) / 4;
-        
-        TreeIndexMultiThreadTestDriver driver = new TreeIndexMultiThreadTestDriver(btree, workerFactory, fieldSerdes, conf.ops, conf.opProbs);
-        driver.init(harness.getBTreeFileId());
-        long[] times = driver.run(numThreads, 1, NUM_OPERATIONS, batchSize);
-        driver.deinit();
-        
-        if (LOGGER.isLoggable(Level.INFO)) {
-            LOGGER.info("BTree MultiThread Test Time: " + times[0] + "ms");
-        }
-        
-        harness.tearDown();
+
+    @Override
+    protected String getIndexTypeName() {
+        return "BTree";
     }
-    
-    @Test
-    public void oneIntKeyAndValueRegular() throws InterruptedException, HyracksDataException, TreeIndexException {        
-        ISerializerDeserializer[] fieldSerdes = new ISerializerDeserializer[] { IntegerSerializerDeserializer.INSTANCE, IntegerSerializerDeserializer.INSTANCE };
-        int numKeys = 1;
-        String dataMsg = "One Int Key And Value";
-        
-        for (TestWorkloadConf conf : workloadConfs) {
-            runTest(fieldSerdes, numKeys, REGULAR_NUM_THREADS, conf, dataMsg);
-            runTest(fieldSerdes, numKeys, EXCESSIVE_NUM_THREADS, conf, dataMsg);
-        }
-    }
-    
-    @Test
-    public void oneStringKeyAndValueRegular() throws InterruptedException, HyracksDataException, TreeIndexException {        
-        ISerializerDeserializer[] fieldSerdes = new ISerializerDeserializer[] { UTF8StringSerializerDeserializer.INSTANCE, UTF8StringSerializerDeserializer.INSTANCE };
-        int numKeys = 1;
-        String dataMsg = "One String Key And Value";
-        
-        for (TestWorkloadConf conf : workloadConfs) {
-            runTest(fieldSerdes, numKeys, REGULAR_NUM_THREADS, conf, dataMsg);
-            runTest(fieldSerdes, numKeys, EXCESSIVE_NUM_THREADS, conf, dataMsg);
-        }
-    }
-    
 }
diff --git a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeTestWorker.java b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeTestWorker.java
index 726163d..0940a5a 100644
--- a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeTestWorker.java
+++ b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeTestWorker.java
@@ -16,6 +16,8 @@
 package edu.uci.ics.hyracks.storage.am.btree.multithread;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleReference;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNonExistentKeyException;
@@ -33,8 +35,16 @@
 
 public class BTreeTestWorker extends AbstractTreeIndexTestWorker {
     
+    private final BTree btree;
+    private final int numKeyFields;
+    private final ArrayTupleBuilder deleteTb;
+    private final ArrayTupleReference deleteTuple = new ArrayTupleReference();
+    
     public BTreeTestWorker(DataGenThread dataGen, TestOperationSelector opSelector, ITreeIndex index, int numBatches) {
         super(dataGen, opSelector, index, numBatches);
+        btree = (BTree) index;
+        numKeyFields = btree.getComparatorFactories().length;
+        deleteTb = new ArrayTupleBuilder(numKeyFields);
     }
     
     @Override
@@ -55,8 +65,14 @@
                 break;
                 
             case DELETE:
+                // Create a tuple reference with only key fields.
+                deleteTb.reset();
+                for (int i = 0; i < numKeyFields; i++) {
+                    deleteTb.addField(tuple.getFieldData(i), tuple.getFieldStart(i), tuple.getFieldLength(i));
+                }
+                deleteTuple.reset(deleteTb.getFieldEndOffsets(), deleteTb.getByteArray());
                 try {
-                    accessor.delete(tuple);
+                    accessor.delete(deleteTuple);
                 } catch (BTreeNonExistentKeyException e) {
                     // Ignore non-existant keys, since we get random tuples.
                 }
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
index cef3e72..fb1b227 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
@@ -32,11 +32,11 @@
 	
 	@Override
 	protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits,
-			IBinaryComparatorFactory[] cmpFactory) throws TreeIndexException {
+			IBinaryComparatorFactory[] cmpFactories) throws TreeIndexException {
 		return LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(),
 				harness.getMemFreePageManager(), harness.getOnDiskDir(),
 				harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
-				typeTraits, cmpFactory);
+				typeTraits, cmpFactories);
 	}
 
 	@Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
new file mode 100644
index 0000000..e3f57e0
--- /dev/null
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
@@ -0,0 +1,108 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.btree.multithread;
+
+import java.util.ArrayList;
+
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.btree.tests.OrderedIndexMultiThreadTest;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+import edu.uci.ics.hyracks.storage.am.common.test.ITreeIndexTestWorkerFactory;
+import edu.uci.ics.hyracks.storage.am.common.test.TestOperationSelector.TestOperation;
+import edu.uci.ics.hyracks.storage.am.common.test.TestWorkloadConf;
+import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestHarness;
+import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeUtils;
+
+public class LSMBTreeMultiThreadTest extends OrderedIndexMultiThreadTest {
+
+    private LSMBTreeTestHarness harness = new LSMBTreeTestHarness();
+    
+    private LSMBTreeTestWorkerFactory workerFactory = new LSMBTreeTestWorkerFactory();
+    
+    @Override
+    protected void setUp() throws HyracksDataException {
+        harness.setUp();
+    }
+
+    @Override
+    protected void tearDown() throws HyracksDataException {
+        harness.tearDown();
+    }
+
+    @Override
+    protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories) throws TreeIndexException {
+        return LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(),
+                harness.getMemFreePageManager(), harness.getOnDiskDir(),
+                harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                typeTraits, cmpFactories);
+    }
+
+    @Override
+    protected ITreeIndexTestWorkerFactory getWorkerFactory() {
+        return workerFactory;
+    }
+
+    @Override
+    protected ArrayList<TestWorkloadConf> getTestWorkloadConf() {
+        ArrayList<TestWorkloadConf> workloadConfs = new ArrayList<TestWorkloadConf>();
+        
+        // Insert only workload.
+        TestOperation[] insertOnlyOps = new TestOperation[] { TestOperation.INSERT };
+        //workloadConfs.add(new TestWorkloadConf(insertOnlyOps, getUniformOpProbs(insertOnlyOps)));
+        
+        // Insert and merge workload.
+        TestOperation[] insertMergeOps = new TestOperation[] { TestOperation.INSERT, TestOperation.MERGE };
+        //workloadConfs.add(new TestWorkloadConf(insertMergeOps, getUniformOpProbs(insertMergeOps)));
+        
+        // Inserts mixed with point searches and scans.
+        TestOperation[] insertSearchOnlyOps = new TestOperation[] { TestOperation.INSERT, TestOperation.POINT_SEARCH, TestOperation.ORDERED_SCAN };
+        //workloadConfs.add(new TestWorkloadConf(insertSearchOnlyOps, getUniformOpProbs(insertSearchOnlyOps)));
+        
+        // Inserts, updates, and deletes.
+        TestOperation[] insertDeleteUpdateOps = new TestOperation[] { TestOperation.INSERT, TestOperation.DELETE, TestOperation.UPDATE };
+        //workloadConfs.add(new TestWorkloadConf(insertDeleteUpdateOps, getUniformOpProbs(insertDeleteUpdateOps)));
+        
+        // Inserts, updates, deletes and merges.
+        TestOperation[] insertDeleteUpdateMergeOps = new TestOperation[] { TestOperation.INSERT, TestOperation.DELETE, TestOperation.UPDATE, TestOperation.MERGE };
+        //workloadConfs.add(new TestWorkloadConf(insertDeleteUpdateMergeOps, getUniformOpProbs(insertDeleteUpdateMergeOps)));
+        
+        // All operations except merge.
+        TestOperation[] allNoMergeOps = new TestOperation[] { TestOperation.INSERT, TestOperation.DELETE, TestOperation.UPDATE, TestOperation.POINT_SEARCH, TestOperation.ORDERED_SCAN };
+        //workloadConfs.add(new TestWorkloadConf(allNoMergeOps, getUniformOpProbs(allNoMergeOps)));
+        
+        // All operations merge.
+        TestOperation[] allOps = new TestOperation[] { TestOperation.INSERT, TestOperation.DELETE, TestOperation.UPDATE, TestOperation.POINT_SEARCH, TestOperation.ORDERED_SCAN, TestOperation.MERGE };
+        //workloadConfs.add(new TestWorkloadConf(allOps, getUniformOpProbs(allOps)));
+        
+        TestOperation[] debugOps = new TestOperation[] { TestOperation.INSERT, TestOperation.POINT_SEARCH, TestOperation.ORDERED_SCAN, TestOperation.MERGE };
+        workloadConfs.add(new TestWorkloadConf(debugOps, getUniformOpProbs(debugOps)));
+        
+        return workloadConfs;
+    }
+
+    @Override
+    protected int getFileId() {
+        return harness.getFileId();
+    }
+
+    @Override
+    protected String getIndexTypeName() {
+        return "LSMBTree";
+    }
+}
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeTestWorker.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeTestWorker.java
new file mode 100644
index 0000000..120cee4
--- /dev/null
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeTestWorker.java
@@ -0,0 +1,135 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.btree.multithread;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleReference;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
+import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNonExistentKeyException;
+import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNotUpdateableException;
+import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
+import edu.uci.ics.hyracks.storage.am.common.test.AbstractTreeIndexTestWorker;
+import edu.uci.ics.hyracks.storage.am.common.test.TestOperationSelector;
+import edu.uci.ics.hyracks.storage.am.common.test.TestOperationSelector.TestOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTree;
+import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTree.LSMBTreeIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMMergeInProgressException;
+
+public class LSMBTreeTestWorker extends AbstractTreeIndexTestWorker {
+    
+    private final LSMBTree lsmBTree;
+    private final int numKeyFields;
+    private final ArrayTupleBuilder deleteTb;
+    private final ArrayTupleReference deleteTuple = new ArrayTupleReference();
+    
+    public LSMBTreeTestWorker(DataGenThread dataGen, TestOperationSelector opSelector, ITreeIndex index, int numBatches) {
+        super(dataGen, opSelector, index, numBatches);
+        lsmBTree = (LSMBTree) index;
+        numKeyFields = lsmBTree.getComparatorFactories().length;
+        deleteTb = new ArrayTupleBuilder(numKeyFields);
+    }
+    
+    @Override
+    public void performOp(ITupleReference tuple, TestOperation op) throws HyracksDataException, TreeIndexException {        
+        LSMBTreeIndexAccessor accessor = (LSMBTreeIndexAccessor) indexAccessor;
+        ITreeIndexCursor searchCursor = accessor.createSearchCursor();
+        MultiComparator cmp = accessor.getMultiComparator();
+        RangePredicate rangePred = new RangePredicate(tuple, tuple, true, true, cmp, cmp);
+        
+        switch (op) {
+            case INSERT:
+                try {
+                    accessor.insert(tuple);
+                } catch (BTreeDuplicateKeyException e) {
+                    // Ignore duplicate keys, since we get random tuples.
+                }
+                break;
+                
+            case DELETE:
+                // Create a tuple reference with only key fields.
+                deleteTb.reset();
+                for (int i = 0; i < numKeyFields; i++) {
+                    deleteTb.addField(tuple.getFieldData(i), tuple.getFieldStart(i), tuple.getFieldLength(i));
+                }
+                deleteTuple.reset(deleteTb.getFieldEndOffsets(), deleteTb.getByteArray());
+                try {
+                    accessor.delete(deleteTuple);
+                } catch (BTreeNonExistentKeyException e) {
+                    // Ignore non-existant keys, since we get random tuples.
+                }
+                break;
+                
+            case UPDATE: 
+                try {
+                    accessor.update(tuple);
+                } catch (BTreeNonExistentKeyException e) {
+                    // Ignore non-existant keys, since we get random tuples.
+                } catch (BTreeNotUpdateableException e) {
+                    // Ignore not updateable exception due to numKeys == numFields.
+                }
+                break;
+                
+            case POINT_SEARCH: 
+                searchCursor.reset();
+                rangePred.setLowKey(tuple, true);
+                rangePred.setHighKey(tuple, true);
+                accessor.search(searchCursor, rangePred);
+                consumeCursorTuples(searchCursor);
+                break;
+                
+            case ORDERED_SCAN:
+                searchCursor.reset();
+                rangePred.setLowKey(null, true);
+                rangePred.setHighKey(null, true);
+                accessor.search(searchCursor, rangePred);
+                consumeCursorTuples(searchCursor);
+                break;
+                
+            case MERGE:
+                try {
+                    accessor.merge();
+                } catch (LSMMergeInProgressException e) {
+                    // Ignore ongoing merges. Do an insert instead.
+                    try {
+                        accessor.insert(tuple);
+                    } catch (BTreeDuplicateKeyException e1) {
+                        // Ignore duplicate keys, since we get random tuples.
+                    }
+                }
+                break;
+                
+            default:
+                throw new HyracksDataException("Op " + op.toString() + " not supported.");
+        }
+    }
+    
+    private void consumeCursorTuples(ITreeIndexCursor cursor) throws HyracksDataException {
+        try {
+            while(cursor.hasNext()) {
+                cursor.next();
+            }
+        } finally {
+            cursor.close();
+        }
+    }
+}
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeTestWorkerFactory.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeTestWorkerFactory.java
new file mode 100644
index 0000000..ac23aaf
--- /dev/null
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeTestWorkerFactory.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.btree.multithread;
+
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
+import edu.uci.ics.hyracks.storage.am.common.test.AbstractTreeIndexTestWorker;
+import edu.uci.ics.hyracks.storage.am.common.test.ITreeIndexTestWorkerFactory;
+import edu.uci.ics.hyracks.storage.am.common.test.TestOperationSelector;
+
+public class LSMBTreeTestWorkerFactory implements ITreeIndexTestWorkerFactory {
+    @Override
+    public AbstractTreeIndexTestWorker create(DataGenThread dataGen, TestOperationSelector opSelector,
+            ITreeIndex index, int numBatches) {
+        return new LSMBTreeTestWorker(dataGen, opSelector, index, numBatches);
+    }
+}
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
index b2db656..531592d 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
@@ -44,7 +44,6 @@
     private static final int DEFAULT_DISK_MAX_OPEN_FILES = 200;
     private static final int DEFAULT_MEM_PAGE_SIZE = 256;
     private static final int DEFAULT_MEM_NUM_PAGES = 100;
-    //private static final int DEFAULT_MEM_NUM_PAGES = 10;
     private static final int DEFAULT_HYRACKS_FRAME_SIZE = 128;
     private static final int DUMMY_FILE_ID = -1;