diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDataflowHelper.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDataflowHelper.java
index 449515f..982f0ed 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDataflowHelper.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDataflowHelper.java
@@ -21,8 +21,8 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.btree.util.BTreeUtils;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.AbstractTreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.ITreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexDataflowHelper;
 
 public class BTreeDataflowHelper extends TreeIndexDataflowHelper {
@@ -32,7 +32,7 @@
 
     @Override
     public ITreeIndex createIndexInstance() throws HyracksDataException {
-        ITreeIndexOperatorDescriptor treeOpDesc = (ITreeIndexOperatorDescriptor) opDesc;
+        AbstractTreeIndexOperatorDescriptor treeOpDesc = (AbstractTreeIndexOperatorDescriptor) opDesc;
         try {
             return BTreeUtils.createBTree(opDesc.getStorageManager().getBufferCache(ctx), opDesc.getStorageManager()
                     .getFileMapProvider(ctx), treeOpDesc.getTreeIndexTypeTraits(), treeOpDesc
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/AbstractTreeIndexOperatorDescriptor.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/AbstractTreeIndexOperatorDescriptor.java
index 52aa5e6..aed3cc9 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/AbstractTreeIndexOperatorDescriptor.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/AbstractTreeIndexOperatorDescriptor.java
@@ -25,8 +25,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITupleFilterFactory;
 import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
 
-public abstract class AbstractTreeIndexOperatorDescriptor extends AbstractIndexOperatorDescriptor implements
-        ITreeIndexOperatorDescriptor {
+public abstract class AbstractTreeIndexOperatorDescriptor extends AbstractIndexOperatorDescriptor {
 
     private static final long serialVersionUID = 1L;
 
@@ -45,12 +44,10 @@
         this.comparatorFactories = comparatorFactories;
     }
 
-    @Override
     public IBinaryComparatorFactory[] getTreeIndexComparatorFactories() {
         return comparatorFactories;
     }
 
-    @Override
     public ITypeTraits[] getTreeIndexTypeTraits() {
         return typeTraits;
     }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/ITreeIndexOperatorDescriptor.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/ITreeIndexOperatorDescriptor.java
deleted file mode 100644
index a646e02..0000000
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/ITreeIndexOperatorDescriptor.java
+++ /dev/null
@@ -1,25 +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.common.dataflow;
-
-import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
-import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
-
-public interface ITreeIndexOperatorDescriptor extends IIndexOperatorDescriptor {
-	public IBinaryComparatorFactory[] getTreeIndexComparatorFactories();
-	
-	public ITypeTraits[] getTreeIndexTypeTraits();
-}
\ No newline at end of file
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 bc73f21..09077e1 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
@@ -19,8 +19,8 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 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.AbstractTreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-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;
@@ -50,7 +50,7 @@
 
     @Override
     public ITreeIndex createIndexInstance() throws HyracksDataException {
-        ITreeIndexOperatorDescriptor treeOpDesc = (ITreeIndexOperatorDescriptor) opDesc;
+        AbstractTreeIndexOperatorDescriptor treeOpDesc = (AbstractTreeIndexOperatorDescriptor) opDesc;
         ITreeIndexMetaDataFrameFactory metaDataFrameFactory = new LIFOMetaDataFrameFactory();
         InMemoryBufferCache memBufferCache = new InMemoryBufferCache(new HeapBufferAllocator(), memPageSize,
                 memNumPages, new TransientFileMapManager());
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 d14e6c2..54c8eac 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
@@ -24,8 +24,8 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 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.AbstractTreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-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;
@@ -69,7 +69,7 @@
     
     @Override
     public ITreeIndex createIndexInstance() throws HyracksDataException {
-        ITreeIndexOperatorDescriptor treeOpDesc = (ITreeIndexOperatorDescriptor) opDesc;
+        AbstractTreeIndexOperatorDescriptor treeOpDesc = (AbstractTreeIndexOperatorDescriptor) opDesc;
         ITreeIndexMetaDataFrameFactory metaDataFrameFactory = new LIFOMetaDataFrameFactory();
         InMemoryBufferCache memBufferCache = new DualIndexInMemoryBufferCache(new HeapBufferAllocator(), memPageSize,
                 memNumPages);
diff --git a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/dataflow/RTreeDataflowHelper.java b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/dataflow/RTreeDataflowHelper.java
index ce6323f..5c3b314 100644
--- a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/dataflow/RTreeDataflowHelper.java
+++ b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/dataflow/RTreeDataflowHelper.java
@@ -19,8 +19,8 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.AbstractTreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.ITreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 import edu.uci.ics.hyracks.storage.am.rtree.util.RTreeUtils;
@@ -39,7 +39,7 @@
 
     @Override
     public ITreeIndex createIndexInstance() throws HyracksDataException {
-        ITreeIndexOperatorDescriptor treeOpDesc = (ITreeIndexOperatorDescriptor) opDesc;
+        AbstractTreeIndexOperatorDescriptor treeOpDesc = (AbstractTreeIndexOperatorDescriptor) opDesc;
         return RTreeUtils.createRTree(treeOpDesc.getStorageManager().getBufferCache(ctx), treeOpDesc
                 .getStorageManager().getFileMapProvider(ctx), treeOpDesc.getTreeIndexTypeTraits(),
                 valueProviderFactories, treeOpDesc.getTreeIndexComparatorFactories(), rtreePolicyType, file);