diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java
index 0298d36..7b0007a 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2010 by The Regents of the University of California
+ * 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
@@ -57,12 +57,16 @@
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexBulkLoadOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexCreateOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ConstantMergePolicyProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.FlushControllerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateSchedulerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexSearchModifierFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.BinaryTokenizerOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.InvertedIndexBulkLoadOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.InvertedIndexCreateOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.InvertedIndexDataflowHelperFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.InvertedIndexSearchOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.LSMInvertedIndexBulkLoadOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.LSMInvertedIndexCreateOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.LSMInvertedIndexDataflowHelperFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.LSMInvertedIndexSearchOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.search.ConjunctiveSearchModifierFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.DelimitedUTF8StringBinaryTokenizerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizerFactory;
@@ -74,15 +78,20 @@
 import edu.uci.ics.hyracks.test.support.TestStorageManagerInterface;
 import edu.uci.ics.hyracks.tests.integration.AbstractIntegrationTest;
 
+@SuppressWarnings("rawtypes")
 public class WordInvertedIndexTest extends AbstractIntegrationTest {
     static {
         TestStorageManagerComponentHolder.init(8192, 20, 20);
     }
 
+    private static final int MERGE_THRESHOLD = 3;
+    
     private IStorageManagerInterface storageManager = new TestStorageManagerInterface();
     private IIndexLifecycleManagerProvider lcManagerProvider = new TestIndexLifecycleManagerProvider();
     private IIndexDataflowHelperFactory btreeDataflowHelperFactory = new BTreeDataflowHelperFactory();
-    private IIndexDataflowHelperFactory invertedIndexDataflowHelperFactory = new InvertedIndexDataflowHelperFactory();
+    private IIndexDataflowHelperFactory invertedIndexDataflowHelperFactory = new LSMInvertedIndexDataflowHelperFactory(new FlushControllerProvider(), new ConstantMergePolicyProvider(
+            ImmediateSchedulerProvider.INSTANCE, MERGE_THRESHOLD), new RefCountingOperationTrackerProvider(),
+            ImmediateSchedulerProvider.INSTANCE);
 
     private final static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
     private final static String sep = System.getProperty("file.separator");
@@ -158,7 +167,7 @@
 
     public void createInvertedIndex() throws Exception {
         JobSpecification spec = new JobSpecification();
-        InvertedIndexCreateOperatorDescriptor invIndexCreateOp = new InvertedIndexCreateOperatorDescriptor(spec,
+        LSMInvertedIndexCreateOperatorDescriptor invIndexCreateOp = new LSMInvertedIndexCreateOperatorDescriptor(spec,
                 storageManager, btreeFileSplitProvider, invListsFileSplitProvider, lcManagerProvider, tokenTypeTraits,
                 tokenComparatorFactories, invListsTypeTraits, invListsComparatorFactories, tokenizerFactory,
                 invertedIndexDataflowHelperFactory, NoOpOperationCallbackProvider.INSTANCE);
@@ -197,7 +206,7 @@
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, primaryBtreeBulkLoad, NC1_ID);
         return primaryBtreeBulkLoad;
     }
-
+    
     private IOperatorDescriptor createScanKeyProviderOp(JobSpecification spec) throws HyracksDataException {
         // build dummy tuple containing nothing
         ArrayTupleBuilder tb = new ArrayTupleBuilder(primaryKeyFieldCount * 2);
@@ -266,7 +275,7 @@
     }
 
     private IOperatorDescriptor createInvertedIndexBulkLoadOp(JobSpecification spec, int[] fieldPermutation) {
-        InvertedIndexBulkLoadOperatorDescriptor invIndexBulkLoadOp = new InvertedIndexBulkLoadOperatorDescriptor(spec,
+        LSMInvertedIndexBulkLoadOperatorDescriptor invIndexBulkLoadOp = new LSMInvertedIndexBulkLoadOperatorDescriptor(spec,
                 fieldPermutation, storageManager, btreeFileSplitProvider, invListsFileSplitProvider, lcManagerProvider,
                 tokenTypeTraits, tokenComparatorFactories, invListsTypeTraits, invListsComparatorFactories,
                 tokenizerFactory, invertedIndexDataflowHelperFactory, NoOpOperationCallbackProvider.INSTANCE);
@@ -311,7 +320,7 @@
 
     private IOperatorDescriptor createInvertedIndexSearchOp(JobSpecification spec,
             IInvertedIndexSearchModifierFactory searchModifierFactory) {
-        InvertedIndexSearchOperatorDescriptor invIndexSearchOp = new InvertedIndexSearchOperatorDescriptor(spec, 0,
+        LSMInvertedIndexSearchOperatorDescriptor invIndexSearchOp = new LSMInvertedIndexSearchOperatorDescriptor(spec, 0,
                 storageManager, btreeFileSplitProvider, invListsFileSplitProvider, lcManagerProvider, tokenTypeTraits,
                 tokenComparatorFactories, invListsTypeTraits, invListsComparatorFactories,
                 invertedIndexDataflowHelperFactory, tokenizerFactory, searchModifierFactory, invListsRecDesc, false,
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 3d3b27f..b6ee9b5 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
@@ -57,7 +57,7 @@
 import edu.uci.ics.hyracks.storage.am.common.impls.AbstractTreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.impls.NodeFrontier;
-import edu.uci.ics.hyracks.storage.am.common.impls.TreeDiskOrderScanCursor;
+import edu.uci.ics.hyracks.storage.am.common.impls.TreeIndexDiskOrderScanCursor;
 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.common.buffercache.IBufferCache;
@@ -86,7 +86,7 @@
     }
 
     private void diskOrderScan(ITreeIndexCursor icursor, BTreeOpContext ctx) throws HyracksDataException {
-        TreeDiskOrderScanCursor cursor = (TreeDiskOrderScanCursor) icursor;
+        TreeIndexDiskOrderScanCursor cursor = (TreeIndexDiskOrderScanCursor) icursor;
         ctx.reset();
         RangePredicate diskOrderScanPred = new RangePredicate(null, null, true, true, ctx.cmp, ctx.cmp);
         int currentPageId = rootPage;
@@ -893,7 +893,7 @@
         @Override
         public ITreeIndexCursor createDiskOrderScanCursor() {
             IBTreeLeafFrame leafFrame = (IBTreeLeafFrame) btree.getLeafFrameFactory().createFrame();
-            return new TreeDiskOrderScanCursor(leafFrame);
+            return new TreeIndexDiskOrderScanCursor(leafFrame);
         }
 
         @Override
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexDataflowHelper.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexDataflowHelper.java
index a712c26..3dd5546 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexDataflowHelper.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexDataflowHelper.java
@@ -1,5 +1,6 @@
 package edu.uci.ics.hyracks.storage.am.common.api;
 
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
@@ -18,4 +19,6 @@
     public FileReference getFileReference();
 
     public long getResourceID();
+    
+    public IHyracksTaskContext getTaskContext();
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexDataflowHelper.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexDataflowHelper.java
index c678844..18a0966 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexDataflowHelper.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexDataflowHelper.java
@@ -121,4 +121,8 @@
     public long getResourceID() {
         return indexArtifactMap.get(file.getFile().getPath());
     }
+    
+    public IHyracksTaskContext getTaskContext() {
+        return ctx;
+    }
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexBulkLoadOperatorNodePushable.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexBulkLoadOperatorNodePushable.java
index 6ec2336..40e9c3e 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexBulkLoadOperatorNodePushable.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexBulkLoadOperatorNodePushable.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2010 by The Regents of the University of California
+ * 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
@@ -23,6 +23,7 @@
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputSinkOperatorNodePushable;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexBulkLoader;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.tuples.PermutingFrameTupleReference;
@@ -32,7 +33,7 @@
     private final IHyracksTaskContext ctx;
     private final float fillFactor;
     private final boolean verifyInput;
-    private final TreeIndexDataflowHelper treeIndexHelper;
+    private final IIndexDataflowHelper indexHelper;
     private FrameTupleAccessor accessor;
     private IIndexBulkLoader bulkLoader;
     private ITreeIndex treeIndex;
@@ -46,8 +47,7 @@
             IRecordDescriptorProvider recordDescProvider) {
         this.opDesc = opDesc;
         this.ctx = ctx;
-        this.treeIndexHelper = (TreeIndexDataflowHelper) opDesc.getIndexDataflowHelperFactory()
-                .createIndexDataflowHelper(opDesc, ctx, partition);
+        this.indexHelper = opDesc.getIndexDataflowHelperFactory().createIndexDataflowHelper(opDesc, ctx, partition);
         this.fillFactor = fillFactor;
         this.verifyInput = verifyInput;
         this.recordDescProvider = recordDescProvider;
@@ -59,12 +59,12 @@
         RecordDescriptor recDesc = recordDescProvider.getInputRecordDescriptor(opDesc.getActivityId(), 0);
         accessor = new FrameTupleAccessor(ctx.getFrameSize(), recDesc);
 
-        treeIndexHelper.open();
-        treeIndex = (ITreeIndex) treeIndexHelper.getIndexInstance();
+        indexHelper.open();
+        treeIndex = (ITreeIndex) indexHelper.getIndexInstance();
         try {
             bulkLoader = treeIndex.createBulkLoader(fillFactor, verifyInput);
         } catch (Exception e) {
-            treeIndexHelper.close();
+            indexHelper.close();
             throw new HyracksDataException(e);
         }
     }
@@ -90,7 +90,7 @@
         } catch (Exception e) {
             throw new HyracksDataException(e);
         } finally {
-            treeIndexHelper.close();
+            indexHelper.close();
         }
     }
 
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexCreateOperatorNodePushable.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexCreateOperatorNodePushable.java
index ee8df92..2534c97 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexCreateOperatorNodePushable.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexCreateOperatorNodePushable.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2010 by The Regents of the University of California
+ * 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
@@ -20,14 +20,14 @@
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractOperatorNodePushable;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexDataflowHelper;
 
 public class TreeIndexCreateOperatorNodePushable extends AbstractOperatorNodePushable {
-    private final TreeIndexDataflowHelper treeIndexHelper;
+    private final IIndexDataflowHelper indexHelper;
 
     public TreeIndexCreateOperatorNodePushable(AbstractTreeIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
-        this.treeIndexHelper = (TreeIndexDataflowHelper) opDesc.getIndexDataflowHelperFactory()
-                .createIndexDataflowHelper(opDesc, ctx, partition);
+        this.indexHelper = opDesc.getIndexDataflowHelperFactory().createIndexDataflowHelper(opDesc, ctx, partition);
     }
 
     @Override
@@ -46,7 +46,7 @@
 
     @Override
     public void initialize() throws HyracksDataException {
-        treeIndexHelper.create();
+        indexHelper.create();
     }
 
     @Override
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexDataflowHelper.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexDataflowHelper.java
index afa8015..0185500 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexDataflowHelper.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexDataflowHelper.java
@@ -19,7 +19,7 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrame;
-import edu.uci.ics.hyracks.storage.am.common.impls.TreeDiskOrderScanCursor;
+import edu.uci.ics.hyracks.storage.am.common.impls.TreeIndexDiskOrderScanCursor;
 
 public abstract class TreeIndexDataflowHelper extends IndexDataflowHelper {
     protected ITreeIndexOperatorDescriptor treeOpDesc;
@@ -30,6 +30,6 @@
     }
 
     public ITreeIndexCursor createDiskOrderScanCursor(ITreeIndexFrame leafFrame) throws HyracksDataException {
-        return new TreeDiskOrderScanCursor(leafFrame);
+        return new TreeIndexDiskOrderScanCursor(leafFrame);
     }
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexDropOperatorNodePushable.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexDropOperatorNodePushable.java
index 6f74e49..6d38a80 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexDropOperatorNodePushable.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexDropOperatorNodePushable.java
@@ -20,14 +20,14 @@
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractOperatorNodePushable;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexDataflowHelper;
 
 public class TreeIndexDropOperatorNodePushable extends AbstractOperatorNodePushable {
-    private final TreeIndexDataflowHelper treeIndexHelper;
+    private final IIndexDataflowHelper indexHelper;
 
     public TreeIndexDropOperatorNodePushable(AbstractTreeIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
-        this.treeIndexHelper = (TreeIndexDataflowHelper) opDesc.getIndexDataflowHelperFactory()
-                .createIndexDataflowHelper(opDesc, ctx, partition);
+        this.indexHelper = opDesc.getIndexDataflowHelperFactory().createIndexDataflowHelper(opDesc, ctx, partition);
     }
 
     @Override
@@ -46,7 +46,7 @@
 
     @Override
     public void initialize() throws HyracksDataException {
-        treeIndexHelper.destroy();
+        indexHelper.destroy();
     }
 
     @Override
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexInsertUpdateDeleteOperatorNodePushable.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexInsertUpdateDeleteOperatorNodePushable.java
index c7c5a9d..a1ba612 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexInsertUpdateDeleteOperatorNodePushable.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexInsertUpdateDeleteOperatorNodePushable.java
@@ -25,6 +25,7 @@
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.FrameTupleReference;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputUnaryOutputOperatorNodePushable;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.ITupleFilter;
@@ -36,7 +37,7 @@
 public class TreeIndexInsertUpdateDeleteOperatorNodePushable extends AbstractUnaryInputUnaryOutputOperatorNodePushable {
     private final AbstractTreeIndexOperatorDescriptor opDesc;
     private final IHyracksTaskContext ctx;
-    private final TreeIndexDataflowHelper treeIndexHelper;
+    private final IIndexDataflowHelper indexHelper;
     private FrameTupleAccessor accessor;
     private final IRecordDescriptorProvider recordDescProvider;
     private final IndexOp op;
@@ -52,8 +53,7 @@
             IRecordDescriptorProvider recordDescProvider, IndexOp op) {
         this.opDesc = opDesc;
         this.ctx = ctx;
-        this.treeIndexHelper = (TreeIndexDataflowHelper) opDesc.getIndexDataflowHelperFactory()
-                .createIndexDataflowHelper(opDesc, ctx, partition);
+        this.indexHelper = opDesc.getIndexDataflowHelperFactory().createIndexDataflowHelper(opDesc, ctx, partition);
         this.recordDescProvider = recordDescProvider;
         this.op = op;
         tuple.setFieldPermutation(fieldPermutation);
@@ -65,19 +65,18 @@
         accessor = new FrameTupleAccessor(ctx.getFrameSize(), inputRecDesc);
         writeBuffer = ctx.allocateFrame();
         writer.open();
-        treeIndexHelper.open();
-        ITreeIndex treeIndex = (ITreeIndex) treeIndexHelper.getIndexInstance();
+        indexHelper.open();
+        ITreeIndex treeIndex = (ITreeIndex) indexHelper.getIndexInstance();
         try {
-            modCallback = opDesc.getOpCallbackProvider().getModificationOperationCallback(
-                    treeIndexHelper.getResourceID());
+            modCallback = opDesc.getOpCallbackProvider().getModificationOperationCallback(indexHelper.getResourceID());
             indexAccessor = treeIndex.createAccessor(modCallback, NoOpOperationCallback.INSTANCE);
             ITupleFilterFactory tupleFilterFactory = opDesc.getTupleFilterFactory();
             if (tupleFilterFactory != null) {
-                tupleFilter = tupleFilterFactory.createTupleFilter(treeIndexHelper.ctx);
+                tupleFilter = tupleFilterFactory.createTupleFilter(indexHelper.getTaskContext());
                 frameTuple = new FrameTupleReference();
             }
         } catch (Exception e) {
-            treeIndexHelper.close();
+            indexHelper.close();
             throw new HyracksDataException(e);
         }
     }
@@ -134,7 +133,7 @@
         try {
             writer.close();
         } finally {
-            treeIndexHelper.close();
+            indexHelper.close();
         }
 
     }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexSearchOperatorNodePushable.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexSearchOperatorNodePushable.java
index 657163c..31fbe18 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexSearchOperatorNodePushable.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/TreeIndexSearchOperatorNodePushable.java
@@ -30,6 +30,7 @@
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputUnaryOutputOperatorNodePushable;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
@@ -39,7 +40,7 @@
 public abstract class TreeIndexSearchOperatorNodePushable extends AbstractUnaryInputUnaryOutputOperatorNodePushable {
     protected final AbstractTreeIndexOperatorDescriptor opDesc;
     protected final IHyracksTaskContext ctx;
-    protected final TreeIndexDataflowHelper treeIndexHelper;
+    protected final IIndexDataflowHelper indexHelper;
     protected FrameTupleAccessor accessor;
 
     protected ByteBuffer writeBuffer;
@@ -61,8 +62,7 @@
             int partition, IRecordDescriptorProvider recordDescProvider) {
         this.opDesc = opDesc;
         this.ctx = ctx;
-        this.treeIndexHelper = (TreeIndexDataflowHelper) opDesc.getIndexDataflowHelperFactory()
-                .createIndexDataflowHelper(opDesc, ctx, partition);
+        this.indexHelper = opDesc.getIndexDataflowHelperFactory().createIndexDataflowHelper(opDesc, ctx, partition);
         this.retainInput = opDesc.getRetainInput();
         this.inputRecDesc = recordDescProvider.getInputRecordDescriptor(opDesc.getActivityId(), 0);
     }
@@ -79,8 +79,8 @@
     public void open() throws HyracksDataException {
         accessor = new FrameTupleAccessor(ctx.getFrameSize(), inputRecDesc);
         writer.open();
-        treeIndexHelper.open();
-        treeIndex = (ITreeIndex) treeIndexHelper.getIndexInstance();
+        indexHelper.open();
+        treeIndex = (ITreeIndex) indexHelper.getIndexInstance();
         try {
             cursorFrame = treeIndex.getLeafFrameFactory().createFrame();
             searchPred = createSearchPredicate();
@@ -90,14 +90,14 @@
             appender = new FrameTupleAppender(ctx.getFrameSize());
             appender.reset(writeBuffer, true);
             ISearchOperationCallback searchCallback = opDesc.getOpCallbackProvider().getSearchOperationCallback(
-                    treeIndexHelper.getResourceID());
+                    indexHelper.getResourceID());
             indexAccessor = treeIndex.createAccessor(NoOpOperationCallback.INSTANCE, searchCallback);
             cursor = createCursor();
             if (retainInput) {
                 frameTuple = new FrameTupleReference();
             }
         } catch (Exception e) {
-            treeIndexHelper.close();
+            indexHelper.close();
             throw new HyracksDataException(e);
         }
     }
@@ -157,7 +157,7 @@
                 throw new HyracksDataException(e);
             }
         } finally {
-            treeIndexHelper.close();
+            indexHelper.close();
         }
     }
 
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/impls/TreeDiskOrderScanCursor.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/impls/TreeIndexDiskOrderScanCursor.java
similarity index 97%
rename from hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/impls/TreeDiskOrderScanCursor.java
rename to hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/impls/TreeIndexDiskOrderScanCursor.java
index 8a094ba..2015ee5 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/impls/TreeDiskOrderScanCursor.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/impls/TreeIndexDiskOrderScanCursor.java
@@ -26,7 +26,7 @@
 import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
 import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
 
-public class TreeDiskOrderScanCursor implements ITreeIndexCursor {
+public class TreeIndexDiskOrderScanCursor implements ITreeIndexCursor {
 
     private int tupleIndex = 0;
     private int fileId = -1;
@@ -39,7 +39,7 @@
     private final ITreeIndexFrame frame;
     private final ITreeIndexTupleReference frameTuple;
 
-    public TreeDiskOrderScanCursor(ITreeIndexFrame frame) {
+    public TreeIndexDiskOrderScanCursor(ITreeIndexFrame frame) {
         this.frame = frame;
         this.frameTuple = frame.createTupleReference();
     }
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
index 5ddd18d..bc73f21 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2010 by The Regents of the University of California
+ * 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
@@ -20,29 +20,20 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexDataflowHelper;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.ITreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeUtils;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.file.TransientFileMapManager;
 
-public class LSMBTreeDataflowHelper extends TreeIndexDataflowHelper {
-    private static int DEFAULT_MEM_PAGE_SIZE = 32768;
-    private static int DEFAULT_MEM_NUM_PAGES = 1000;
-
-    private final int memPageSize;
-    private final int memNumPages;
-
-    private final ILSMFlushController flushController;
-    private final ILSMMergePolicy mergePolicy;
-    private final ILSMOperationTracker opTracker;
-    private final ILSMIOOperationScheduler ioScheduler;
+public class LSMBTreeDataflowHelper extends AbstractLSMIndexDataflowHelper {
 
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
@@ -54,17 +45,12 @@
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             int memPageSize, int memNumPages, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
             ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
-        super(opDesc, ctx, partition);
-        this.memPageSize = memPageSize;
-        this.memNumPages = memNumPages;
-        this.flushController = flushController;
-        this.mergePolicy = mergePolicy;
-        this.opTracker = opTracker;
-        this.ioScheduler = ioScheduler;
+        super(opDesc, ctx, partition, memPageSize, memNumPages, flushController, mergePolicy, opTracker, ioScheduler);
     }
 
     @Override
     public ITreeIndex createIndexInstance() throws HyracksDataException {
+        ITreeIndexOperatorDescriptor treeOpDesc = (ITreeIndexOperatorDescriptor) opDesc;
         ITreeIndexMetaDataFrameFactory metaDataFrameFactory = new LIFOMetaDataFrameFactory();
         InMemoryBufferCache memBufferCache = new InMemoryBufferCache(new HeapBufferAllocator(), memPageSize,
                 memNumPages, new TransientFileMapManager());
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
index 79d1b9e..347a153 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
@@ -16,30 +16,22 @@
 package edu.uci.ics.hyracks.storage.am.lsm.btree.dataflow;
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelperFactory;
 
-public class LSMBTreeDataflowHelperFactory implements IIndexDataflowHelperFactory {
+public class LSMBTreeDataflowHelperFactory extends AbstractLSMIndexDataflowHelperFactory {
 
     private static final long serialVersionUID = 1L;
 
-    private final ILSMFlushControllerProvider flushControllerProvider;
-    private final ILSMMergePolicyProvider mergePolicyProvider;
-    private final ILSMOperationTrackerProvider opTrackerProvider;
-    private final ILSMIOOperationSchedulerProvider ioSchedulerProvider;
-
     public LSMBTreeDataflowHelperFactory(ILSMFlushControllerProvider flushControllerProvider,
             ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
             ILSMIOOperationSchedulerProvider ioSchedulerProvider) {
-        this.flushControllerProvider = flushControllerProvider;
-        this.mergePolicyProvider = mergePolicyProvider;
-        this.opTrackerProvider = opTrackerProvider;
-        this.ioSchedulerProvider = ioSchedulerProvider;
+        super(flushControllerProvider, mergePolicyProvider, opTrackerProvider, ioSchedulerProvider);
     }
 
     @Override
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
new file mode 100644
index 0000000..e85c7ea
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
@@ -0,0 +1,57 @@
+/*
+ * 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.dataflow;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+
+public abstract class AbstractLSMIndexDataflowHelper extends IndexDataflowHelper {
+
+    protected static int DEFAULT_MEM_PAGE_SIZE = 32768;
+    protected static int DEFAULT_MEM_NUM_PAGES = 1000;
+
+    protected final int memPageSize;
+    protected final int memNumPages;
+
+    protected final ILSMFlushController flushController;
+    protected final ILSMMergePolicy mergePolicy;
+    protected final ILSMOperationTracker opTracker;
+    protected final ILSMIOOperationScheduler ioScheduler;
+
+    public AbstractLSMIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOOperationScheduler ioScheduler) {
+        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, flushController, mergePolicy,
+                opTracker, ioScheduler);
+    }
+
+    public AbstractLSMIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
+            int memPageSize, int memNumPages, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
+        super(opDesc, ctx, partition);
+        this.memPageSize = memPageSize;
+        this.memNumPages = memNumPages;
+        this.flushController = flushController;
+        this.mergePolicy = mergePolicy;
+        this.opTracker = opTracker;
+        this.ioScheduler = ioScheduler;
+    }
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
new file mode 100644
index 0000000..27a4d47
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
@@ -0,0 +1,40 @@
+/*
+ * 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.dataflow;
+
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+
+public abstract class AbstractLSMIndexDataflowHelperFactory implements IIndexDataflowHelperFactory {
+    protected static final long serialVersionUID = 1L;
+
+    protected final ILSMFlushControllerProvider flushControllerProvider;
+    protected final ILSMMergePolicyProvider mergePolicyProvider;
+    protected final ILSMOperationTrackerProvider opTrackerProvider;
+    protected final ILSMIOOperationSchedulerProvider ioSchedulerProvider;
+
+    public AbstractLSMIndexDataflowHelperFactory(ILSMFlushControllerProvider flushControllerProvider,
+            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider) {
+        this.flushControllerProvider = flushControllerProvider;
+        this.mergePolicyProvider = mergePolicyProvider;
+        this.opTrackerProvider = opTrackerProvider;
+        this.ioSchedulerProvider = ioSchedulerProvider;
+    }
+}
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/api/IInvertedIndexOperatorDescriptor.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/api/IInvertedIndexOperatorDescriptor.java
index a48b9a6..173261b 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/api/IInvertedIndexOperatorDescriptor.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/api/IInvertedIndexOperatorDescriptor.java
@@ -22,11 +22,11 @@
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizerFactory;
 
 public interface IInvertedIndexOperatorDescriptor extends ITreeIndexOperatorDescriptor {
+    public ITypeTraits[] getInvListsTypeTraits();
+    
     public IBinaryComparatorFactory[] getInvListsComparatorFactories();
 
-    public IBinaryTokenizerFactory getTokenizerFactory();
-    
-    public ITypeTraits[] getInvListsTypeTraits();
+    public IBinaryTokenizerFactory getTokenizerFactory();        
     
     public IFileSplitProvider getInvListsFileSplitProvider();
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/AbstractInvertedIndexOperatorDescriptor.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/AbstractLSMInvertedIndexOperatorDescriptor.java
similarity index 93%
rename from hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/AbstractInvertedIndexOperatorDescriptor.java
rename to hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/AbstractLSMInvertedIndexOperatorDescriptor.java
index 49f58b7..56c8405 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/AbstractInvertedIndexOperatorDescriptor.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/AbstractLSMInvertedIndexOperatorDescriptor.java
@@ -29,7 +29,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizerFactory;
 import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
 
-public abstract class AbstractInvertedIndexOperatorDescriptor extends AbstractSingleActivityOperatorDescriptor
+public abstract class AbstractLSMInvertedIndexOperatorDescriptor extends AbstractSingleActivityOperatorDescriptor
         implements IInvertedIndexOperatorDescriptor {
 
     private static final long serialVersionUID = 1L;
@@ -42,7 +42,7 @@
 
     // Btree.
     protected final ITypeTraits[] tokenTypeTraits;
-    protected final IBinaryComparatorFactory[] btreeComparatorFactories;
+    protected final IBinaryComparatorFactory[] tokenComparatorFactories;
     protected final IFileSplitProvider btreeFileSplitProvider;
 
     // Inverted index.
@@ -52,7 +52,7 @@
     protected final IFileSplitProvider invListsFileSplitProvider;
     protected final IIndexDataflowHelperFactory invertedIndexDataflowHelperFactory;
 
-    public AbstractInvertedIndexOperatorDescriptor(IOperatorDescriptorRegistry spec, int inputArity, int outputArity,
+    public AbstractLSMInvertedIndexOperatorDescriptor(IOperatorDescriptorRegistry spec, int inputArity, int outputArity,
             RecordDescriptor recDesc, IStorageManagerInterface storageManager,
             IFileSplitProvider btreeFileSplitProvider, IFileSplitProvider invListsFileSplitProvider,
             IIndexLifecycleManagerProvider lifecycleManagerProvider, ITypeTraits[] tokenTypeTraits,
@@ -70,7 +70,7 @@
 
         // Btree.
         this.tokenTypeTraits = tokenTypeTraits;
-        this.btreeComparatorFactories = tokenComparatorFactories;
+        this.tokenComparatorFactories = tokenComparatorFactories;
         this.btreeFileSplitProvider = btreeFileSplitProvider;
 
         // Inverted index.
@@ -102,7 +102,7 @@
 
     @Override
     public IBinaryComparatorFactory[] getTreeIndexComparatorFactories() {
-        return btreeComparatorFactories;
+        return tokenComparatorFactories;
     }
 
     @Override
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexDataflowHelper.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexDataflowHelper.java
deleted file mode 100644
index b515122..0000000
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexDataflowHelper.java
+++ /dev/null
@@ -1,52 +0,0 @@
-/*
- * 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.invertedindex.dataflow;
-
-import java.io.File;
-
-import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.io.FileReference;
-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.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedListBuilder;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.ondisk.FixedSizeElementInvertedListBuilder;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.ondisk.OnDiskInvertedIndex;
-
-public final class InvertedIndexDataflowHelper extends IndexDataflowHelper {
-
-    public InvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition) {
-        super(opDesc, ctx, partition);
-    }
-
-    @Override
-    public IIndex createIndexInstance() throws HyracksDataException {
-        IInvertedIndexOperatorDescriptor invIndexOpDesc = (IInvertedIndexOperatorDescriptor) opDesc;
-        IInvertedListBuilder invListBuilder = new FixedSizeElementInvertedListBuilder(
-                invIndexOpDesc.getInvListsTypeTraits());
-        FileReference btreeFile = new FileReference(new File(file.getFile().getPath() + "_btree"));
-        try {
-            return new OnDiskInvertedIndex(opDesc.getStorageManager().getBufferCache(ctx), opDesc.getStorageManager()
-                    .getFileMapProvider(ctx), invListBuilder, invIndexOpDesc.getInvListsTypeTraits(),
-                    invIndexOpDesc.getInvListsComparatorFactories(), invIndexOpDesc.getTreeIndexTypeTraits(),
-                    invIndexOpDesc.getTreeIndexComparatorFactories(), btreeFile, file);
-        } catch (IndexException e) {
-            throw new HyracksDataException(e);
-        }
-    }
-}
\ 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/dataflow/InvertedIndexDataflowHelperFactory.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexDataflowHelperFactory.java
deleted file mode 100644
index 814ff4a..0000000
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexDataflowHelperFactory.java
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * 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.invertedindex.dataflow;
-
-import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-
-public class InvertedIndexDataflowHelperFactory implements IIndexDataflowHelperFactory {
-
-    private static final long serialVersionUID = 1L;
-
-    @Override
-    public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            int partition) {
-        return new InvertedIndexDataflowHelper(opDesc, ctx, partition);
-    }
-
-}
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexBulkLoadOperatorDescriptor.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexBulkLoadOperatorDescriptor.java
similarity index 89%
rename from hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexBulkLoadOperatorDescriptor.java
rename to hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexBulkLoadOperatorDescriptor.java
index 616b0e5..e67c664 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexBulkLoadOperatorDescriptor.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexBulkLoadOperatorDescriptor.java
@@ -28,13 +28,13 @@
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizerFactory;
 import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
 
-public class InvertedIndexBulkLoadOperatorDescriptor extends AbstractInvertedIndexOperatorDescriptor {
+public class LSMInvertedIndexBulkLoadOperatorDescriptor extends AbstractLSMInvertedIndexOperatorDescriptor {
 
     private static final long serialVersionUID = 1L;
 
     private final int[] fieldPermutation;
 
-    public InvertedIndexBulkLoadOperatorDescriptor(IOperatorDescriptorRegistry spec, int[] fieldPermutation,
+    public LSMInvertedIndexBulkLoadOperatorDescriptor(IOperatorDescriptorRegistry spec, int[] fieldPermutation,
             IStorageManagerInterface storageManager, IFileSplitProvider btreeFileSplitProvider,
             IFileSplitProvider invListsFileSplitProvider, IIndexLifecycleManagerProvider lifecycleManagerProvider,
             ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenComparatorFactories,
@@ -51,6 +51,6 @@
     @Override
     public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
-        return new InvertedIndexBulkLoadOperatorNodePushable(this, ctx, partition, fieldPermutation, recordDescProvider);
+        return new LSMInvertedIndexBulkLoadOperatorNodePushable(this, ctx, partition, fieldPermutation, recordDescProvider);
     }
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexBulkLoadOperatorNodePushable.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexBulkLoadOperatorNodePushable.java
similarity index 82%
rename from hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexBulkLoadOperatorNodePushable.java
rename to hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexBulkLoadOperatorNodePushable.java
index 6fa447c..a84aea5 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexBulkLoadOperatorNodePushable.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexBulkLoadOperatorNodePushable.java
@@ -24,15 +24,16 @@
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputSinkOperatorNodePushable;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexBulkLoader;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexDataflowHelper;
 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.tuples.PermutingFrameTupleReference;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.ondisk.OnDiskInvertedIndex;
 
-public class InvertedIndexBulkLoadOperatorNodePushable extends AbstractUnaryInputSinkOperatorNodePushable {
-    private final AbstractInvertedIndexOperatorDescriptor opDesc;
+public class LSMInvertedIndexBulkLoadOperatorNodePushable extends AbstractUnaryInputSinkOperatorNodePushable {
+    private final AbstractLSMInvertedIndexOperatorDescriptor opDesc;
     private final IHyracksTaskContext ctx;
-    private final InvertedIndexDataflowHelper invIndexDataflowHelper;
-    private OnDiskInvertedIndex invIndex;
+    private final IIndexDataflowHelper invIndexDataflowHelper;
+    private IIndex invIndex;
     private IIndexBulkLoader bulkLoader;
 
     private FrameTupleAccessor accessor;
@@ -40,11 +41,12 @@
 
     private IRecordDescriptorProvider recordDescProvider;
 
-    public InvertedIndexBulkLoadOperatorNodePushable(AbstractInvertedIndexOperatorDescriptor opDesc,
+    public LSMInvertedIndexBulkLoadOperatorNodePushable(AbstractLSMInvertedIndexOperatorDescriptor opDesc,
             IHyracksTaskContext ctx, int partition, int[] fieldPermutation, IRecordDescriptorProvider recordDescProvider) {
         this.opDesc = opDesc;
         this.ctx = ctx;
-        this.invIndexDataflowHelper = new InvertedIndexDataflowHelper(opDesc, ctx, partition);
+        this.invIndexDataflowHelper = opDesc.getIndexDataflowHelperFactory().createIndexDataflowHelper(opDesc, ctx,
+                partition);
         this.recordDescProvider = recordDescProvider;
         tuple.setFieldPermutation(fieldPermutation);
     }
@@ -53,9 +55,9 @@
     public void open() throws HyracksDataException {
         RecordDescriptor recDesc = recordDescProvider.getInputRecordDescriptor(opDesc.getActivityId(), 0);
         accessor = new FrameTupleAccessor(ctx.getFrameSize(), recDesc);
-        
+
         invIndexDataflowHelper.open();
-        invIndex = (OnDiskInvertedIndex) invIndexDataflowHelper.getIndexInstance();
+        invIndex = invIndexDataflowHelper.getIndexInstance();
         try {
             bulkLoader = invIndex.createBulkLoader(BTree.DEFAULT_FILL_FACTOR, false);
         } catch (Exception e) {
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexCreateOperatorDescriptor.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexCreateOperatorDescriptor.java
similarity index 90%
rename from hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexCreateOperatorDescriptor.java
rename to hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexCreateOperatorDescriptor.java
index c81806d..d310034 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexCreateOperatorDescriptor.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexCreateOperatorDescriptor.java
@@ -28,11 +28,11 @@
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizerFactory;
 import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
 
-public class InvertedIndexCreateOperatorDescriptor extends AbstractInvertedIndexOperatorDescriptor {
+public class LSMInvertedIndexCreateOperatorDescriptor extends AbstractLSMInvertedIndexOperatorDescriptor {
 
     private static final long serialVersionUID = 1L;
 
-    public InvertedIndexCreateOperatorDescriptor(IOperatorDescriptorRegistry spec,
+    public LSMInvertedIndexCreateOperatorDescriptor(IOperatorDescriptorRegistry spec,
             IStorageManagerInterface storageManager, IFileSplitProvider btreeFileSplitProvider,
             IFileSplitProvider invListsFileSplitProvider, IIndexLifecycleManagerProvider lifecycleManagerProvider,
             ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenComparatorFactories,
@@ -47,6 +47,6 @@
     @Override
     public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
-        return new InvertedIndexCreateOperatorNodePushable(this, ctx, partition);
+        return new LSMInvertedIndexCreateOperatorNodePushable(this, ctx, partition);
     }
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexCreateOperatorNodePushable.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexCreateOperatorNodePushable.java
similarity index 76%
rename from hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexCreateOperatorNodePushable.java
rename to hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexCreateOperatorNodePushable.java
index 5ad4f15..a0da8b9 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexCreateOperatorNodePushable.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexCreateOperatorNodePushable.java
@@ -19,13 +19,14 @@
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractOperatorNodePushable;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexDataflowHelper;
 
-public class InvertedIndexCreateOperatorNodePushable extends AbstractOperatorNodePushable {
-    private final InvertedIndexDataflowHelper invIndexDataflowHelper;
+public class LSMInvertedIndexCreateOperatorNodePushable extends AbstractOperatorNodePushable {
+    private final IIndexDataflowHelper indexHelper;
 
-    public InvertedIndexCreateOperatorNodePushable(AbstractInvertedIndexOperatorDescriptor opDesc,
+    public LSMInvertedIndexCreateOperatorNodePushable(AbstractLSMInvertedIndexOperatorDescriptor opDesc,
             IHyracksTaskContext ctx, int partition) {
-        this.invIndexDataflowHelper = new InvertedIndexDataflowHelper(opDesc, ctx, partition);
+        this.indexHelper = opDesc.getIndexDataflowHelperFactory().createIndexDataflowHelper(opDesc, ctx, partition);
     }
 
     @Override
@@ -44,7 +45,7 @@
 
     @Override
     public void initialize() throws HyracksDataException {
-        invIndexDataflowHelper.create();
+        indexHelper.create();
     }
 
     @Override
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
new file mode 100644
index 0000000..1582cb0
--- /dev/null
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
@@ -0,0 +1,92 @@
+/*
+ * 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.invertedindex.dataflow;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
+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.dataflow.IIndexOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
+import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.impls.LSMInvertedIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.util.InvertedIndexUtils;
+import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
+import edu.uci.ics.hyracks.storage.common.file.TransientFileMapManager;
+
+public final class LSMInvertedIndexDataflowHelper extends IndexDataflowHelper {
+
+    private static int DEFAULT_MEM_PAGE_SIZE = 32768;
+    private static int DEFAULT_MEM_NUM_PAGES = 1000;
+
+    private final int memPageSize;
+    private final int memNumPages;
+
+    private final ILSMFlushController flushController;
+    private final ILSMMergePolicy mergePolicy;
+    private final ILSMOperationTracker opTracker;
+    private final ILSMIOOperationScheduler ioScheduler;
+
+    public LSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOOperationScheduler ioScheduler) {
+        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, flushController, mergePolicy,
+                opTracker, ioScheduler);
+    }
+
+    public LSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
+            int memPageSize, int memNumPages, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
+        super(opDesc, ctx, partition);
+        this.memPageSize = memPageSize;
+        this.memNumPages = memNumPages;
+        this.flushController = flushController;
+        this.mergePolicy = mergePolicy;
+        this.opTracker = opTracker;
+        this.ioScheduler = ioScheduler;
+    }
+    
+    @Override
+    public IIndex createIndexInstance() throws HyracksDataException {
+        IInvertedIndexOperatorDescriptor invIndexOpDesc = (IInvertedIndexOperatorDescriptor) opDesc;
+        try {
+            ITreeIndexMetaDataFrameFactory metaDataFrameFactory = new LIFOMetaDataFrameFactory();
+            InMemoryBufferCache memBufferCache = new InMemoryBufferCache(new HeapBufferAllocator(), memPageSize,
+                    memNumPages, new TransientFileMapManager());
+            InMemoryFreePageManager memFreePageManager = new InMemoryFreePageManager(memNumPages, metaDataFrameFactory);
+            IBufferCache diskBufferCache = opDesc.getStorageManager().getBufferCache(ctx);
+            IFileMapProvider diskFileMapProvider = opDesc.getStorageManager().getFileMapProvider(ctx);
+            LSMInvertedIndex invIndex = InvertedIndexUtils.createLSMInvertedIndex(memBufferCache, memFreePageManager,
+                    diskFileMapProvider, invIndexOpDesc.getInvListsTypeTraits(),
+                    invIndexOpDesc.getInvListsComparatorFactories(), invIndexOpDesc.getTreeIndexTypeTraits(),
+                    invIndexOpDesc.getTreeIndexComparatorFactories(), invIndexOpDesc.getTokenizerFactory(),
+                    diskBufferCache, ctx.getIOManager(), file.getFile().getPath(), flushController, mergePolicy,
+                    opTracker, ioScheduler);
+            return invIndex;
+        } catch (IndexException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+}
\ 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/dataflow/LSMInvertedIndexDataflowHelperFactory.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
new file mode 100644
index 0000000..0bdf1ea
--- /dev/null
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
@@ -0,0 +1,45 @@
+/*
+ * 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.dataflow;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelperFactory;
+
+public class LSMInvertedIndexDataflowHelperFactory extends AbstractLSMIndexDataflowHelperFactory {
+
+    private static final long serialVersionUID = 1L;
+
+    public LSMInvertedIndexDataflowHelperFactory(ILSMFlushControllerProvider flushControllerProvider,
+            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider) {
+        super(flushControllerProvider, mergePolicyProvider, opTrackerProvider, ioSchedulerProvider);
+    }
+
+    @Override
+    public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
+            int partition) {
+        return new LSMInvertedIndexDataflowHelper(opDesc, ctx, partition, flushControllerProvider.getFlushController(),
+                mergePolicyProvider.getMergePolicy(), opTrackerProvider.getOperationTracker(),
+                ioSchedulerProvider.getIOScheduler());
+    }
+
+}
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexSearchOperatorDescriptor.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexSearchOperatorDescriptor.java
similarity index 91%
rename from hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexSearchOperatorDescriptor.java
rename to hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexSearchOperatorDescriptor.java
index 5738cab..59665c2 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexSearchOperatorDescriptor.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexSearchOperatorDescriptor.java
@@ -32,13 +32,13 @@
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizerFactory;
 import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
 
-public class InvertedIndexSearchOperatorDescriptor extends AbstractInvertedIndexOperatorDescriptor {
+public class LSMInvertedIndexSearchOperatorDescriptor extends AbstractLSMInvertedIndexOperatorDescriptor {
     private static final long serialVersionUID = 1L;
 
     private final int queryField;
     private final IInvertedIndexSearchModifierFactory searchModifierFactory;
 
-    public InvertedIndexSearchOperatorDescriptor(IOperatorDescriptorRegistry spec, int queryField,
+    public LSMInvertedIndexSearchOperatorDescriptor(IOperatorDescriptorRegistry spec, int queryField,
             IStorageManagerInterface storageManager, IFileSplitProvider btreeFileSplitProvider,
             IFileSplitProvider invListsFileSplitProvider, IIndexLifecycleManagerProvider lifecycleManagerProvider,
             ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenComparatorFactories,
@@ -58,7 +58,7 @@
     public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) throws HyracksDataException {
         IInvertedIndexSearchModifier searchModifier = searchModifierFactory.createSearchModifier();
-        return new InvertedIndexSearchOperatorNodePushable(this, ctx, partition, queryField, searchModifier,
+        return new LSMInvertedIndexSearchOperatorNodePushable(this, ctx, partition, queryField, searchModifier,
                 recordDescProvider);
     }
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexSearchOperatorNodePushable.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexSearchOperatorNodePushable.java
similarity index 90%
rename from hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexSearchOperatorNodePushable.java
rename to hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexSearchOperatorNodePushable.java
index 2b79b6b..5c9a92b 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/InvertedIndexSearchOperatorNodePushable.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexSearchOperatorNodePushable.java
@@ -31,21 +31,22 @@
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputUnaryOutputOperatorNodePushable;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexDataflowHelper;
+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.lsm.invertedindex.api.IInvertedIndexSearchModifier;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.exceptions.OccurrenceThresholdPanicException;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.ondisk.OnDiskInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.search.InvertedIndexSearchPredicate;
 
-public class InvertedIndexSearchOperatorNodePushable extends AbstractUnaryInputUnaryOutputOperatorNodePushable {
-    private final AbstractInvertedIndexOperatorDescriptor opDesc;
+public class LSMInvertedIndexSearchOperatorNodePushable extends AbstractUnaryInputUnaryOutputOperatorNodePushable {
+    private final AbstractLSMInvertedIndexOperatorDescriptor opDesc;
     private final IHyracksTaskContext ctx;
-    private final InvertedIndexDataflowHelper invIndexDataflowHelper;
+    private final IIndexDataflowHelper invIndexDataflowHelper;
     private final int queryField;
     private FrameTupleAccessor accessor;
     private FrameTupleReference tuple;
     private IRecordDescriptorProvider recordDescProvider;
-    private OnDiskInvertedIndex invIndex;
+    private IIndex invIndex;
 
     private final InvertedIndexSearchPredicate searchPred;
     private IIndexAccessor indexAccessor;
@@ -58,12 +59,13 @@
 
     private final boolean retainInput;
 
-    public InvertedIndexSearchOperatorNodePushable(AbstractInvertedIndexOperatorDescriptor opDesc,
+    public LSMInvertedIndexSearchOperatorNodePushable(AbstractLSMInvertedIndexOperatorDescriptor opDesc,
             IHyracksTaskContext ctx, int partition, int queryField, IInvertedIndexSearchModifier searchModifier,
             IRecordDescriptorProvider recordDescProvider) {
         this.opDesc = opDesc;
         this.ctx = ctx;
-        this.invIndexDataflowHelper = new InvertedIndexDataflowHelper(opDesc, ctx, partition);
+        this.invIndexDataflowHelper = opDesc.getIndexDataflowHelperFactory().createIndexDataflowHelper(opDesc, ctx,
+                partition);
         this.queryField = queryField;
         this.searchPred = new InvertedIndexSearchPredicate(opDesc.getTokenizerFactory().createTokenizer(),
                 searchModifier);
@@ -78,7 +80,7 @@
         tuple = new FrameTupleReference();
 
         invIndexDataflowHelper.open();
-        invIndex = (OnDiskInvertedIndex) invIndexDataflowHelper.getIndexInstance();
+        invIndex = invIndexDataflowHelper.getIndexInstance();
         try {
             writeBuffer = ctx.allocateFrame();
             tb = new ArrayTupleBuilder(recordDesc.getFieldCount());
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursorInitialState.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursorInitialState.java
index 712014d..b44206d 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursorInitialState.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursorInitialState.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2010 by The Regents of the University of California
+ * 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
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
index 53769b6..d14e6c2 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
@@ -25,35 +25,27 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexDataflowHelper;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.ITreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
-public abstract class AbstractLSMRTreeDataflowHelper extends TreeIndexDataflowHelper {
-    private static int DEFAULT_MEM_PAGE_SIZE = 32768;
-    private static int DEFAULT_MEM_NUM_PAGES = 1000;
-
-    private final int memPageSize;
-    private final int memNumPages;
+public abstract class AbstractLSMRTreeDataflowHelper extends AbstractLSMIndexDataflowHelper {
 
     protected final IBinaryComparatorFactory[] btreeComparatorFactories;
     protected final IPrimitiveValueProviderFactory[] valueProviderFactories;
     protected final RTreePolicyType rtreePolicyType;
-    protected final ILSMFlushController flushController;
-    protected final ILSMMergePolicy mergePolicy;
-    protected final ILSMOperationTracker opTracker;
-    protected final ILSMIOOperationScheduler ioScheduler;
 
     public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             IBinaryComparatorFactory[] btreeComparatorFactories,
@@ -69,26 +61,20 @@
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
             ILSMIOOperationScheduler ioScheduler) {
-        super(opDesc, ctx, partition);
-        this.memPageSize = memPageSize;
-        this.memNumPages = memNumPages;
+        super(opDesc, ctx, partition, memPageSize, memNumPages, flushController, mergePolicy, opTracker, ioScheduler);
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
-        this.flushController = flushController;
-        this.mergePolicy = mergePolicy;
-        this.opTracker = opTracker;
-        this.ioScheduler = ioScheduler;
     }
-
+    
     @Override
     public ITreeIndex createIndexInstance() throws HyracksDataException {
+        ITreeIndexOperatorDescriptor treeOpDesc = (ITreeIndexOperatorDescriptor) opDesc;
         ITreeIndexMetaDataFrameFactory metaDataFrameFactory = new LIFOMetaDataFrameFactory();
         InMemoryBufferCache memBufferCache = new DualIndexInMemoryBufferCache(new HeapBufferAllocator(), memPageSize,
                 memNumPages);
         InMemoryFreePageManager memFreePageManager = new DualIndexInMemoryFreePageManager(memNumPages,
                 metaDataFrameFactory);
-
         return createLSMTree(memBufferCache, memFreePageManager, ctx.getIOManager(), file, opDesc.getStorageManager()
                 .getBufferCache(ctx), opDesc.getStorageManager().getFileMapProvider(ctx),
                 treeOpDesc.getTreeIndexTypeTraits(), treeOpDesc.getTreeIndexComparatorFactories(),
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
index 39c431c..8aab803 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2010 by The Regents of the University of California
+ * 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
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
index 37d26a2..a287473 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
@@ -18,38 +18,31 @@
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 
-public class LSMRTreeDataflowHelperFactory implements IIndexDataflowHelperFactory {
+public class LSMRTreeDataflowHelperFactory extends AbstractLSMIndexDataflowHelperFactory {
 
     private static final long serialVersionUID = 1L;
 
     private final IBinaryComparatorFactory[] btreeComparatorFactories;
     private final IPrimitiveValueProviderFactory[] valueProviderFactories;
     private final RTreePolicyType rtreePolicyType;
-    private final ILSMFlushControllerProvider flushControllerProvider;
-    private final ILSMMergePolicyProvider mergePolicyProvider;
-    private final ILSMOperationTrackerProvider opTrackerProvider;
-    private final ILSMIOOperationSchedulerProvider ioSchedulerProvider;
 
     public LSMRTreeDataflowHelperFactory(IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType, IBinaryComparatorFactory[] btreeComparatorFactories,
             ILSMFlushControllerProvider flushControllerProvider, ILSMMergePolicyProvider mergePolicyProvider,
             ILSMOperationTrackerProvider opTrackerProvider, ILSMIOOperationSchedulerProvider ioSchedulerProvider) {
+        super(flushControllerProvider, mergePolicyProvider, opTrackerProvider, ioSchedulerProvider);
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
-        this.flushControllerProvider = flushControllerProvider;
-        this.mergePolicyProvider = mergePolicyProvider;
-        this.opTrackerProvider = opTrackerProvider;
-        this.ioSchedulerProvider = ioSchedulerProvider;
     }
 
     @Override
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 7f2e0b6..73b6708 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
@@ -42,7 +42,7 @@
 import edu.uci.ics.hyracks.storage.am.common.frames.FrameOpSpaceStatus;
 import edu.uci.ics.hyracks.storage.am.common.impls.AbstractTreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.impls.NodeFrontier;
-import edu.uci.ics.hyracks.storage.am.common.impls.TreeDiskOrderScanCursor;
+import edu.uci.ics.hyracks.storage.am.common.impls.TreeIndexDiskOrderScanCursor;
 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.common.util.TreeIndexUtils;
@@ -751,7 +751,7 @@
     }
 
     private void diskOrderScan(ITreeIndexCursor icursor, RTreeOpContext ctx) throws HyracksDataException {
-        TreeDiskOrderScanCursor cursor = (TreeDiskOrderScanCursor) icursor;
+        TreeIndexDiskOrderScanCursor cursor = (TreeIndexDiskOrderScanCursor) icursor;
         ctx.reset();
 
         MultiComparator cmp = MultiComparator.create(cmpFactories);
@@ -831,7 +831,7 @@
 
         @Override
         public ITreeIndexCursor createDiskOrderScanCursor() {
-            return new TreeDiskOrderScanCursor(leafFrameFactory.createFrame());
+            return new TreeIndexDiskOrderScanCursor(leafFrameFactory.createFrame());
         }
 
         @Override
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexExamplesTest.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexExamplesTest.java
index 54d0c93..3962d06 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexExamplesTest.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexExamplesTest.java
@@ -46,7 +46,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexAccessor;
 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.impls.TreeDiskOrderScanCursor;
+import edu.uci.ics.hyracks.storage.am.common.impls.TreeIndexDiskOrderScanCursor;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 
 @SuppressWarnings("rawtypes")
@@ -646,7 +646,7 @@
                 LOGGER.info("Disk-Order Scan:");
             }
             ITreeIndexAccessor treeIndexAccessor = (ITreeIndexAccessor) indexAccessor;
-            TreeDiskOrderScanCursor diskOrderCursor = (TreeDiskOrderScanCursor) treeIndexAccessor
+            TreeIndexDiskOrderScanCursor diskOrderCursor = (TreeIndexDiskOrderScanCursor) treeIndexAccessor
                     .createDiskOrderScanCursor();
             treeIndexAccessor.diskOrderScan(diskOrderCursor);
             try {
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeExamplesTest.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeExamplesTest.java
index fd6a973..e88a259 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeExamplesTest.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeExamplesTest.java
@@ -41,7 +41,7 @@
 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.impls.NoOpOperationCallback;
-import edu.uci.ics.hyracks.storage.am.common.impls.TreeDiskOrderScanCursor;
+import edu.uci.ics.hyracks.storage.am.common.impls.TreeIndexDiskOrderScanCursor;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 import edu.uci.ics.hyracks.storage.am.rtree.impls.SearchPredicate;
@@ -521,7 +521,7 @@
                 LOGGER.info("Disk-Order Scan:");
             }
             ITreeIndexAccessor treeIndexAccessor = (ITreeIndexAccessor) indexAccessor;
-            TreeDiskOrderScanCursor diskOrderCursor = (TreeDiskOrderScanCursor) treeIndexAccessor
+            TreeIndexDiskOrderScanCursor diskOrderCursor = (TreeIndexDiskOrderScanCursor) treeIndexAccessor
                     .createDiskOrderScanCursor();
             treeIndexAccessor.diskOrderScan(diskOrderCursor);
             try {