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 fd7e418..6cbc9d7 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
@@ -451,7 +451,7 @@
         }
 
         @Override
-        public void end() throws HyracksDataException {
+        public void end() throws HyracksDataException, IndexException {
             bulkLoader.end();
             lsmHarness.addBulkLoadedComponent(diskBTree);
         }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
index 82b702b..49e20dd 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
@@ -39,7 +39,7 @@
 
     public void flush(ILSMIOOperation operation) throws HyracksDataException, IndexException;
 
-    public void addBulkLoadedComponent(Object index) throws HyracksDataException;
+    public void addBulkLoadedComponent(Object index) throws HyracksDataException, IndexException;
     
     public ILSMIndex getIndex();
 
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
index a90b64e..a775a78 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
@@ -43,7 +43,8 @@
     public void search(IIndexCursor cursor, List<Object> diskComponents, ISearchPredicate pred, IIndexOpContext ictx,
             boolean includeMemComponent, AtomicInteger searcherRefCount) throws HyracksDataException, IndexException;
 
-    public ILSMIOOperation createMergeOperation(ILSMIOOperationCallback callback) throws HyracksDataException;
+    public ILSMIOOperation createMergeOperation(ILSMIOOperationCallback callback) throws HyracksDataException,
+            IndexException;
 
     public Object merge(List<Object> mergedComponents, ILSMIOOperation operation) throws HyracksDataException,
             IndexException;
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java
index b768cfd..a5ef536 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java
@@ -20,7 +20,6 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMMergeInProgressException;
 
 /**
  * Client handle for performing operations
@@ -33,7 +32,7 @@
     public ILSMIOOperation createFlushOperation(ILSMIOOperationCallback callback);
 
     public ILSMIOOperation createMergeOperation(ILSMIOOperationCallback callback) throws HyracksDataException,
-            LSMMergeInProgressException;
+           IndexException;
 
     /**
      * Force a flush of the in-memory component.
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java
index 2a1f0e7..877c6ffd 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java
@@ -1,8 +1,23 @@
+/*
+ * Copyright 2009-2012 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.api;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 
 public interface ILSMMergePolicy {
-    public void diskComponentAdded(ILSMIndex index, int totalNumDiskComponents) throws HyracksDataException;
+    public void diskComponentAdded(ILSMIndex index, int totalNumDiskComponents) throws HyracksDataException, IndexException;
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
index 8140b0e..4705566 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
@@ -1,6 +1,22 @@
+/*
+ * Copyright 2009-2012 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.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
@@ -20,7 +36,7 @@
     }
 
     @Override
-    public void diskComponentAdded(final ILSMIndex index, int totalNumDiskComponents) throws HyracksDataException {
+    public void diskComponentAdded(final ILSMIndex index, int totalNumDiskComponents) throws HyracksDataException, IndexException {
         if (totalNumDiskComponents >= threshold) {
             ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
                     NoOpOperationCallback.INSTANCE);
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 047d305..ef4bad8 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
@@ -153,8 +153,7 @@
         return diskComponentSnapshot;
     }
 
-    public ILSMIOOperation createMergeOperation(ILSMIOOperationCallback callback) throws LSMMergeInProgressException,
-            HyracksDataException {
+    public ILSMIOOperation createMergeOperation(ILSMIOOperationCallback callback) throws HyracksDataException, IndexException {
         if (!isMerging.compareAndSet(false, true)) {
             throw new LSMMergeInProgressException(
                     "Merge already in progress. Only one merge process allowed at a time.");
@@ -237,7 +236,8 @@
         searcherRefCount.decrementAndGet();
     }
 
-    public void addBulkLoadedComponent(Object index) throws HyracksDataException {
+    @Override
+    public void addBulkLoadedComponent(Object index) throws HyracksDataException, IndexException {
         // The implementation of this call must take any necessary steps to make
         // the new component permanent, and mark it as valid (usually this means
         // forcing all pages of the tree to disk, possibly with some extra
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 8676b27..2a986f8 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
@@ -84,7 +84,7 @@
 
     @Override
     public ILSMIOOperation createMergeOperation(ILSMIOOperationCallback callback) throws HyracksDataException,
-            LSMMergeInProgressException {
+            IndexException {
         return lsmHarness.createMergeOperation(callback);
     }
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
index db43255..7156c8b 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
@@ -65,6 +65,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.impls.LSMInvertedIndexFileManager.LSMInvertedIndexFileNameComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.inmemory.InMemoryInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.inmemory.InMemoryInvertedIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.ondisk.OnDiskInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.ondisk.OnDiskInvertedIndexFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.search.InvertedIndexSearchPredicate;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizerFactory;
@@ -75,11 +76,11 @@
 public class LSMInvertedIndex implements ILSMIndex, IInvertedIndex {
 	public class LSMInvertedIndexComponent {
         private final IInvertedIndex invIndex;
-        private final BTree deleteKeysBTree;
+        private final BTree deletedKeysBTree;
 
-        LSMInvertedIndexComponent(IInvertedIndex invIndex, BTree deleteKeysBTree) {
+        LSMInvertedIndexComponent(IInvertedIndex invIndex, BTree deletedKeysBTree) {
             this.invIndex = invIndex;
-            this.deleteKeysBTree = deleteKeysBTree;
+            this.deletedKeysBTree = deletedKeysBTree;
         }
 
         public IInvertedIndex getInvIndex() {
@@ -87,7 +88,7 @@
         }
 
         public BTree getDeletedKeysBTree() {
-            return deleteKeysBTree;
+            return deletedKeysBTree;
         }
     }
 	
@@ -288,7 +289,7 @@
     public IIndexAccessor createAccessor(IModificationOperationCallback modificationCallback,
             ISearchOperationCallback searchCallback) {
         // TODO: Ignore opcallbacks for now.
-        return new LSMInvertedIndexAccessor(lsmHarness, fileManager, createOpContext());
+        return new LSMInvertedIndexAccessor(this, lsmHarness, fileManager, createOpContext());
     }
     
     private LSMInvertedIndexOpContext createOpContext() {
@@ -296,9 +297,39 @@
     }
     
     @Override
-    public ILSMIOOperation createMergeOperation(ILSMIOOperationCallback callback) throws HyracksDataException {
-        // TODO Auto-generated method stub
-        return null;
+    public ILSMIOOperation createMergeOperation(ILSMIOOperationCallback callback) throws HyracksDataException,
+            IndexException {
+        LSMInvertedIndexOpContext ctx = createOpContext();
+        ctx.reset(IndexOp.SEARCH);
+        IIndexCursor cursor = new LSMInvertedIndexRangeSearchCursor();
+        RangePredicate mergePred = new RangePredicate(null, null, true, true, null, null);
+
+        // Scan diskInvertedIndexes ignoring the memoryInvertedIndex.
+        List<Object> mergingComponents = lsmHarness.search(cursor, mergePred, ctx, false);
+        if (mergingComponents.size() <= 1) {
+            cursor.close();
+            return null;
+        }
+
+        LSMInvertedIndexComponent firstComponent = (LSMInvertedIndexComponent) mergingComponents.get(0);
+        OnDiskInvertedIndex firstInvIndex = (OnDiskInvertedIndex) firstComponent.getInvIndex();
+        String firstFileName = firstInvIndex.getBTree().getFileReference().getFile().getName();
+
+        LSMInvertedIndexComponent lastComponent = (LSMInvertedIndexComponent) mergingComponents.get(mergingComponents
+                .size() - 1);
+        OnDiskInvertedIndex lastInvIndex = (OnDiskInvertedIndex) lastComponent.getInvIndex();
+        String lastFileName = lastInvIndex.getBTree().getFileReference().getFile().getName();
+
+        LSMInvertedIndexFileNameComponent fileNameComponent = (LSMInvertedIndexFileNameComponent) fileManager
+                .getRelMergeFileName(firstFileName, lastFileName);
+        FileReference dictBTreeFileRef = fileManager.createMergeFile(fileNameComponent.getDictBTreeFileName());
+        FileReference deletedKeysBTreeFileRef = fileManager.createMergeFile(fileNameComponent
+                .getDeletedKeysBTreeFileName());
+
+        LSMInvertedIndexMergeOperation mergeOp = new LSMInvertedIndexMergeOperation(this, mergingComponents, cursor,
+                dictBTreeFileRef, deletedKeysBTreeFileRef, callback);
+
+        return mergeOp;
     }
     
     @Override
@@ -357,24 +388,10 @@
             IndexException {
         LSMInvertedIndexMergeOperation mergeOp = (LSMInvertedIndexMergeOperation) operation;
 
-        LSMInvertedIndexOpContext ctx = createOpContext();
-        ctx.reset(IndexOp.SEARCH);
-        IIndexCursor cursor = new LSMInvertedIndexRangeSearchCursor();
-        RangePredicate mergePred = new RangePredicate(null, null, true, true, null, null);
-
-        // Scan diskInvertedIndexes ignoring the memoryInvertedIndex.
-        List<Object> mergingComponents = lsmHarness.search(cursor, mergePred, ctx, false);
-        mergedComponents.addAll(mergingComponents);
-
-        // Nothing to merge.
-        if (mergedComponents.size() <= 1) {
-            cursor.close();
-            return null;
-        }
-
         // Create an inverted index instance.
         IInvertedIndex mergedDiskInvertedIndex = createDiskInvIndex(diskInvIndexFactory,
                 mergeOp.getDictBTreeMergeTarget(), true);
+        IIndexCursor cursor = mergeOp.getCursor();
         IIndexBulkLoader invIndexBulkLoader = mergedDiskInvertedIndex.createBulkLoader(1.0f, false);
         try {
             while (cursor.hasNext()) {
@@ -388,11 +405,15 @@
         invIndexBulkLoader.end();
 
         // Create an empty deleted keys BTree (do nothing with the returned index).
-        createDiskTree(deletedKeysBTreeFactory, mergeOp.getDeletedKeysBTreeMergeTarget(), true);
+        BTree deletedKeysBTree = (BTree) createDiskTree(deletedKeysBTreeFactory,
+                mergeOp.getDeletedKeysBTreeMergeTarget(), true);
 
-        return mergedDiskInvertedIndex;
+        // Add the merged components for cleanup.
+        mergedComponents.addAll(mergeOp.getMergingComponents());
+        
+        return new LSMInvertedIndexComponent(mergedDiskInvertedIndex, deletedKeysBTree);
     }
-
+    
     @Override
     public void addMergedComponent(Object newComponent, List<Object> mergedComponents) {
         diskComponents.removeAll(mergedComponents);
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java
index 050fb02..c6d30d1 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java
@@ -28,7 +28,6 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMHarness;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMMergeInProgressException;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedListCursor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.impls.LSMInvertedIndexFileManager.LSMInvertedIndexFileNameComponent;
@@ -38,11 +37,13 @@
     protected final LSMHarness lsmHarness;    
     protected final ILSMIndexFileManager fileManager;
     protected final IIndexOpContext ctx;
+    protected final LSMInvertedIndex invIndex;
     
-    public LSMInvertedIndexAccessor(LSMHarness lsmHarness, ILSMIndexFileManager fileManager, IIndexOpContext ctx) {
+    public LSMInvertedIndexAccessor(LSMInvertedIndex invIndex, LSMHarness lsmHarness, ILSMIndexFileManager fileManager, IIndexOpContext ctx) {
         this.lsmHarness = lsmHarness;
         this.fileManager = fileManager;
         this.ctx = ctx;
+        this.invIndex = invIndex;
     }
 
     public void insert(ITupleReference tuple) throws HyracksDataException, IndexException {
@@ -78,9 +79,9 @@
     
     @Override
     public ILSMIOOperation createMergeOperation(ILSMIOOperationCallback callback) throws HyracksDataException,
-            LSMMergeInProgressException {
-        // TODO Auto-generated method stub
-        return null;
+            IndexException {
+        ILSMIOOperation mergeOp = invIndex.createMergeOperation(callback);
+        return mergeOp;
     }
 
     @Override
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMergeOperation.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMergeOperation.java
index 5169c57..afae347 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMergeOperation.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMergeOperation.java
@@ -21,7 +21,7 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IODeviceHandle;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
@@ -34,12 +34,12 @@
 public class LSMInvertedIndexMergeOperation implements ILSMIOOperation {
     private final ILSMIndex index;
     private final List<Object> mergingComponents;
-    private final ITreeIndexCursor cursor;
+    private final IIndexCursor cursor;
     private final FileReference dictBTreeMergeTarget;
     private final FileReference deletedKeysBTreeMergeTarget;
     private final ILSMIOOperationCallback callback;
 
-    public LSMInvertedIndexMergeOperation(ILSMIndex index, List<Object> mergingComponents, ITreeIndexCursor cursor,
+    public LSMInvertedIndexMergeOperation(ILSMIndex index, List<Object> mergingComponents, IIndexCursor cursor,
             FileReference dictBTreeMergeTarget, FileReference deletedKeysBTreeMergeTarget, ILSMIOOperationCallback callback) {
         this.index = index;
         this.mergingComponents = mergingComponents;
@@ -89,7 +89,7 @@
         return deletedKeysBTreeMergeTarget;
     }
 
-    public ITreeIndexCursor getCursor() {
+    public IIndexCursor getCursor() {
         return cursor;
     }
 
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
index cdaa233..8873653 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
@@ -20,34 +20,25 @@
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 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.invertedindex.api.IInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexAccessor;
 
 public class LSMInvertedIndexOpContext implements IIndexOpContext {
-    
+
     private IndexOp op;
-    //private final MultiComparator cmp;
-    //private final int invListFieldCount;
-    //private final int tokenFieldCount;
     private final IInvertedIndex memInvIndex;
     private final IIndex memDeletedKeysBTree;
-    
+
     // Accessor to the in-memory inverted index.
     public IInvertedIndexAccessor insertAccessor;
     // Accessor to the deleted-keys BTree.
     public IIndexAccessor deleteAccessor;
-    
+
     public LSMInvertedIndexOpContext(IInvertedIndex memInvIndex, IIndex memDeletedKeysBTree) {
         this.memInvIndex = memInvIndex;
         this.memDeletedKeysBTree = memDeletedKeysBTree;
-        /*
-    	this.cmp = MultiComparator.create(btree.getComparatorFactories());
-    	this.invListFieldCount = memoryBTreeInvertedIndex.getInvListCmpFactories().length;
-    	this.tokenFieldCount = cmp.getKeyFieldCount() - invListFieldCount;
-    	*/
     }
-    
+
     @Override
     public void reset() {
     }
@@ -58,31 +49,23 @@
         switch (newOp) {
             case INSERT: {
                 if (insertAccessor == null) {
-                    insertAccessor = (IInvertedIndexAccessor) memInvIndex.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+                    insertAccessor = (IInvertedIndexAccessor) memInvIndex.createAccessor(
+                            NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
                 }
                 break;
             }
             case DELETE: {
                 if (deleteAccessor == null) {
-                    deleteAccessor = memDeletedKeysBTree.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+                    deleteAccessor = memDeletedKeysBTree.createAccessor(NoOpOperationCallback.INSTANCE,
+                            NoOpOperationCallback.INSTANCE);
                 }
                 break;
             }
         }
         op = newOp;
     }
-    
-    /*
-    public int getInvListFieldCount() {
-    	return invListFieldCount;
+
+    public IndexOp getOp() {
+        return op;
     }
-    
-    public int getTokenFieldCount() {
-    	return tokenFieldCount;
-    }
-    
-    public MultiComparator getComparator() {
-    	return cmp;
-    }
-    */
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/ondisk/OnDiskInvertedIndexRangeSearchCursor.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/ondisk/OnDiskInvertedIndexRangeSearchCursor.java
index e4c9110..85743ca 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/ondisk/OnDiskInvertedIndexRangeSearchCursor.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/ondisk/OnDiskInvertedIndexRangeSearchCursor.java
@@ -122,6 +122,7 @@
         if (unpinNeeded) {
             invListCursor.unpinPages();
         }
+        btreeCursor.close();
         open(null, btreePred);
     }
 
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
index 1b0bf50..335a847 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
@@ -409,7 +409,7 @@
         }
 
         @Override
-        public void end() throws HyracksDataException {
+        public void end() throws HyracksDataException, IndexException {
             bulkLoader.end();
             LSMRTreeComponent diskComponent = new LSMRTreeComponent(diskRTree, diskBTree);
             lsmHarness.addBulkLoadedComponent(diskComponent);
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
index cd0a764..28c6586 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
@@ -361,7 +361,7 @@
         }
 
         @Override
-        public void end() throws HyracksDataException {
+        public void end() throws HyracksDataException, IndexException {
             bulkLoader.end();
             lsmHarness.addBulkLoadedComponent(diskRTree);
         }
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/config/AccessMethodTestsConfig.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/config/AccessMethodTestsConfig.java
index 1b4ddf2..da0cd9a 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/config/AccessMethodTestsConfig.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/config/AccessMethodTestsConfig.java
@@ -69,12 +69,13 @@
     public static final int LSM_BTREE_HYRACKS_FRAME_SIZE = 128;
 
     // Mem configuration for Inverted Index.
-    public static final int INVINDEX_PAGE_SIZE = 32768;
-    public static final int INVINDEX_NUM_PAGES = 100;
-    public static final int INVINDEX_MAX_OPEN_FILES = 10;
-    public static final int INVINDEX_HYRACKS_FRAME_SIZE = 32768;
+    public static final int LSM_INVINDEX_PAGE_SIZE = 32768;
+    public static final int LSM_INVINDEX_NUM_PAGES = 100;
+    public static final int LSM_INVINDEX_MAX_OPEN_FILES = 10;
+    public static final int LSM_INVINDEX_HYRACKS_FRAME_SIZE = 32768;
     
-    public static final int INVINDEX_NUM_BULKLOAD_ROUNDS = 5;
+    public static final int LSM_INVINDEX_NUM_BULKLOAD_ROUNDS = 5;
+    public static final int LSM_INVINDEX_MAX_TREES_TO_MERGE = 5;
     
 }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/LSMInvertedIndexMergeTest.java b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/LSMInvertedIndexMergeTest.java
new file mode 100644
index 0000000..8bd2d4b
--- /dev/null
+++ b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/LSMInvertedIndexMergeTest.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2009-2012 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.invertedindex;
+
+import java.io.IOException;
+
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
+import edu.uci.ics.hyracks.storage.am.common.datagen.TupleGenerator;
+import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
+import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoOpIOOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.common.AbstractInvertedIndexLoadTest;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.util.InvertedIndexTestContext;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.util.InvertedIndexTestContext.InvertedIndexType;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.util.InvertedIndexTestUtils;
+
+public class LSMInvertedIndexMergeTest extends AbstractInvertedIndexLoadTest {
+
+    private final int maxTreesToMerge = AccessMethodTestsConfig.LSM_INVINDEX_MAX_TREES_TO_MERGE;
+    
+    public LSMInvertedIndexMergeTest() {
+        super(InvertedIndexType.LSM, true, 5);
+    }
+
+    @Override
+    protected void runTest(InvertedIndexTestContext testCtx, TupleGenerator tupleGen) throws IOException,
+            IndexException {
+        IIndex invIndex = testCtx.getIndex();        
+        invIndex.create();
+        invIndex.activate();
+        ILSMIndexAccessor invIndexAccessor = (ILSMIndexAccessor) invIndex.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+
+        for (int i = 0; i < maxTreesToMerge; i++) {
+            for (int j = 0; j < i; j++) {
+                if (bulkLoad) {
+                    InvertedIndexTestUtils.bulkLoadInvIndex(testCtx, tupleGen, NUM_DOCS_TO_INSERT);
+                } else {
+                    InvertedIndexTestUtils.insertIntoInvIndex(testCtx, tupleGen, NUM_DOCS_TO_INSERT);
+                }
+
+                // Perform merge.
+                ILSMIOOperation ioop = invIndexAccessor.createMergeOperation(NoOpIOOperationCallback.INSTANCE);
+                if (ioop != null) {
+                    invIndexAccessor.merge(ioop);
+                }
+                
+                // Validate index and compare against expected index.
+                invIndex.validate();
+                if (invIndexType == InvertedIndexType.INMEMORY || invIndexType == InvertedIndexType.ONDISK) {
+                    // This comparison method exercises different features of these types of inverted indexes.
+                    InvertedIndexTestUtils.compareActualAndExpectedIndexes(testCtx);
+                }
+                InvertedIndexTestUtils.compareActualAndExpectedIndexesRangeSearch(testCtx);
+            }
+        }
+        
+        invIndex.deactivate();
+        invIndex.destroy();
+    }
+}
diff --git a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/LSMInvertedIndexMultiBulkLoadTest.java b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/LSMInvertedIndexMultiBulkLoadTest.java
index 19745f7..f360165 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/LSMInvertedIndexMultiBulkLoadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/LSMInvertedIndexMultiBulkLoadTest.java
@@ -22,6 +22,6 @@
 public class LSMInvertedIndexMultiBulkLoadTest extends AbstractInvertedIndexLoadTest {
 
     public LSMInvertedIndexMultiBulkLoadTest() {
-        super(InvertedIndexType.LSM, true, AccessMethodTestsConfig.INVINDEX_NUM_BULKLOAD_ROUNDS);
+        super(InvertedIndexType.LSM, true, AccessMethodTestsConfig.LSM_INVINDEX_NUM_BULKLOAD_ROUNDS);
     }
 }
diff --git a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/AbstractInvertedIndexLoadTest.java b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/AbstractInvertedIndexLoadTest.java
index 29e6639..39e438f 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/AbstractInvertedIndexLoadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/AbstractInvertedIndexLoadTest.java
@@ -53,7 +53,7 @@
             // Validate index and compare against expected index.
             invIndex.validate();
             if (invIndexType == InvertedIndexType.INMEMORY || invIndexType == InvertedIndexType.ONDISK) {
-                // This comparison method exercises different features of these types of inverted-indexes.
+                // This comparison method exercises different features of these types of inverted indexes.
                 InvertedIndexTestUtils.compareActualAndExpectedIndexes(testCtx);                
             }
             InvertedIndexTestUtils.compareActualAndExpectedIndexesRangeSearch(testCtx);