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 b9a3863..7dcfce2 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
@@ -257,10 +257,12 @@
     }
 
     private void insert(ITupleReference tuple, BTreeOpContext ctx) throws HyracksDataException, TreeIndexException {
+        ctx.modificationCallback.commence(tuple);
         insertUpdateOrDelete(tuple, ctx);
     }
 
     private void upsert(ITupleReference tuple, BTreeOpContext ctx) throws HyracksDataException, TreeIndexException {
+        ctx.modificationCallback.commence(tuple);
         insertUpdateOrDelete(tuple, ctx);
     }
 
@@ -271,10 +273,12 @@
         if (fieldCount == ctx.cmp.getKeyFieldCount()) {
             throw new BTreeNotUpdateableException("Cannot perform updates when the entire tuple forms the key.");
         }
+        ctx.modificationCallback.commence(tuple);
         insertUpdateOrDelete(tuple, ctx);
     }
 
     private void delete(ITupleReference tuple, BTreeOpContext ctx) throws HyracksDataException, TreeIndexException {
+        ctx.modificationCallback.commence(tuple);
         insertUpdateOrDelete(tuple, ctx);
     }
 
@@ -284,6 +288,7 @@
         FrameOpSpaceStatus spaceStatus = ctx.leafFrame.hasSpaceInsert(tuple);
         switch (spaceStatus) {
             case SUFFICIENT_CONTIGUOUS_SPACE: {
+                ctx.modificationCallback.found(null);
                 ctx.leafFrame.insert(tuple, targetTupleIndex);
                 ctx.splitKey.reset();
                 break;
@@ -293,6 +298,7 @@
                 if (slotsChanged) {
                     targetTupleIndex = ctx.leafFrame.findInsertTupleIndex(tuple);
                 }
+                ctx.modificationCallback.found(null);
                 ctx.leafFrame.insert(tuple, targetTupleIndex);
                 ctx.splitKey.reset();
                 break;
@@ -306,6 +312,7 @@
                     spaceStatus = ctx.leafFrame.hasSpaceInsert(tuple);
                 }
                 if (spaceStatus == FrameOpSpaceStatus.SUFFICIENT_CONTIGUOUS_SPACE) {
+                    ctx.modificationCallback.found(null);
                     ctx.leafFrame.insert(tuple, targetTupleIndex);
                     ctx.splitKey.reset();
                 } else {
@@ -338,7 +345,11 @@
 
             // Perform an update (delete + insert) if the updateTupleIndex != -1
             if (updateTupleIndex != -1) {
+                ITupleReference beforeTuple = ctx.leafFrame.getUpsertBeforeTuple(tuple, updateTupleIndex);
+                ctx.modificationCallback.found(beforeTuple);
                 ctx.leafFrame.delete(tuple, updateTupleIndex);
+            } else {
+                ctx.modificationCallback.found(null);
             }
             ctx.leafFrame.split(rightFrame, tuple, ctx.splitKey);
 
@@ -371,20 +382,24 @@
     private boolean updateLeaf(ITupleReference tuple, int oldTupleIndex, int pageId, BTreeOpContext ctx)
             throws Exception {
         FrameOpSpaceStatus spaceStatus = ctx.leafFrame.hasSpaceUpdate(tuple, oldTupleIndex);
+        ITupleReference beforeTuple = ctx.leafFrame.getUpsertBeforeTuple(tuple, oldTupleIndex);
         boolean restartOp = false;
         switch (spaceStatus) {
             case SUFFICIENT_INPLACE_SPACE: {
+                ctx.modificationCallback.found(beforeTuple);
                 ctx.leafFrame.update(tuple, oldTupleIndex, true);
                 ctx.splitKey.reset();
                 break;
             }
             case SUFFICIENT_CONTIGUOUS_SPACE: {
+                ctx.modificationCallback.found(beforeTuple);
                 ctx.leafFrame.update(tuple, oldTupleIndex, false);
                 ctx.splitKey.reset();
                 break;
             }
             case SUFFICIENT_SPACE: {
                 // Delete the old tuple, compact the frame, and insert the new tuple.
+                ctx.modificationCallback.found(beforeTuple);
                 ctx.leafFrame.delete(tuple, oldTupleIndex);
                 ctx.leafFrame.compact();
                 int targetTupleIndex = ctx.leafFrame.findInsertTupleIndex(tuple);
@@ -475,6 +490,8 @@
             throw new BTreeNonExistentKeyException("Trying to delete a tuple with a nonexistent key in leaf node.");
         }
         int tupleIndex = ctx.leafFrame.findDeleteTupleIndex(tuple);
+        ITupleReference beforeTuple = ctx.leafFrame.getUpsertBeforeTuple(tuple, tupleIndex);
+        ctx.modificationCallback.found(beforeTuple);
         ctx.leafFrame.delete(tuple, tupleIndex);
         return false;
     }
@@ -878,9 +895,10 @@
         }
     }
 
-    private BTreeOpContext createOpContext() {
+    private BTreeOpContext createOpContext(IModificationOperationCallback modificationCallback,
+            ISearchOperationCallback searchCallback) {
         return new BTreeOpContext(leafFrameFactory, interiorFrameFactory, freePageManager.getMetaDataFrameFactory()
-                .createFrame(), cmpFactories);
+                .createFrame(), cmpFactories, modificationCallback, searchCallback);
     }
 
     public ITreeIndexFrameFactory getInteriorFrameFactory() {
@@ -1007,8 +1025,9 @@
     }
 
     @Override
-    public ITreeIndexAccessor createAccessor(IModificationOperationCallback modificationCallback, ISearchOperationCallback searchCallback) {
-        return new BTreeAccessor(this);
+    public ITreeIndexAccessor createAccessor(IModificationOperationCallback modificationCallback,
+            ISearchOperationCallback searchCallback) {
+        return new BTreeAccessor(this, modificationCallback, searchCallback);
     }
 
     // TODO: Class should be private. But currently we need to expose the
@@ -1017,9 +1036,10 @@
         private BTree btree;
         private BTreeOpContext ctx;
 
-        public BTreeAccessor(BTree btree) {
+        public BTreeAccessor(BTree btree, IModificationOperationCallback modificationCalback,
+                ISearchOperationCallback searchCallback) {
             this.btree = btree;
-            this.ctx = btree.createOpContext();
+            this.ctx = btree.createOpContext(modificationCalback, searchCallback);
         }
 
         @Override
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java
index 23a14eb6..d19b083 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java
@@ -19,6 +19,8 @@
 import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeInteriorFrame;
 import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexOpContext;
+import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
@@ -39,15 +41,18 @@
     public ITreeIndexCursor cursor;
     public BTreeCursorInitialState cursorInitialState;
     public RangePredicate pred;
-    public BTreeSplitKey splitKey;    
+    public BTreeSplitKey splitKey;
     public LongArrayList pageLsns;
     public IntArrayList smPages;
     public IntArrayList freePages;
     public int opRestarts = 0;
     public boolean exceptionHandled;
-    
+    public IModificationOperationCallback modificationCallback;
+    public ISearchOperationCallback searchCallback;
+
     public BTreeOpContext(ITreeIndexFrameFactory leafFrameFactory, ITreeIndexFrameFactory interiorFrameFactory,
-            ITreeIndexMetaDataFrame metaFrame, IBinaryComparatorFactory[] cmpFactories) {
+            ITreeIndexMetaDataFrame metaFrame, IBinaryComparatorFactory[] cmpFactories,
+            IModificationOperationCallback modificationCallback, ISearchOperationCallback searchCallback) {
         this.cmp = MultiComparator.create(cmpFactories);
         this.leafFrameFactory = leafFrameFactory;
         this.leafFrame = (IBTreeLeafFrame) leafFrameFactory.createFrame();
@@ -61,6 +66,8 @@
         }
         this.metaFrame = metaFrame;
         this.pageLsns = new LongArrayList(INIT_ARRAYLIST_SIZE, INIT_ARRAYLIST_SIZE);
+        this.modificationCallback = modificationCallback;
+        this.searchCallback = searchCallback;
     }
 
     public void reset() {
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 a57cef7..07d63d8 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.IModificationOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.IOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.ITupleFilter;
@@ -92,6 +93,9 @@
                     }
                 }
                 tuple.reset(accessor, i);
+                IModificationOperationCallback modificationCallback = callbackProvider
+                        .getModificationOperationCallback();
+                modificationCallback.before(tuple);
                 switch (op) {
                     case INSERT: {
                         indexAccessor.insert(tuple);
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
index 547cf2d..2f253e9 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
@@ -287,7 +287,7 @@
     }
 
     public ITreeIndex merge(List<Object> mergedComponents) throws HyracksDataException, IndexException {
-        LSMBTreeOpContext ctx = createOpContext();
+        LSMBTreeOpContext ctx = createOpContext(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
         ITreeIndexCursor cursor = new LSMBTreeRangeSearchCursor();
         RangePredicate rangePred = new RangePredicate(null, null, true, true, null, null);
         // Ordered scan, ignoring the in-memory BTree.
@@ -427,14 +427,16 @@
         return cmpFactories;
     }
 
-    public LSMBTreeOpContext createOpContext() {
-        return new LSMBTreeOpContext(memBTree, insertLeafFrameFactory, deleteLeafFrameFactory);
+    public LSMBTreeOpContext createOpContext(IModificationOperationCallback modificationCallback,
+            ISearchOperationCallback searchCallback) {
+        return new LSMBTreeOpContext(memBTree, insertLeafFrameFactory, deleteLeafFrameFactory, modificationCallback,
+                searchCallback);
     }
 
     @Override
     public IIndexAccessor createAccessor(IModificationOperationCallback modificationCallback,
             ISearchOperationCallback searchCallback) {
-        return new LSMBTreeIndexAccessor(lsmHarness, createOpContext());
+        return new LSMBTreeIndexAccessor(lsmHarness, createOpContext(modificationCallback, searchCallback));
     }
 
     public class LSMBTreeIndexAccessor extends LSMTreeIndexAccessor {
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
index d94dc52..ca281ed 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
@@ -19,8 +19,9 @@
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeOpContext;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexOpContext;
+import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
-import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOp;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 
@@ -35,9 +36,12 @@
     public BTreeOpContext memBTreeOpCtx;
     public IndexOp op;
     public final MultiComparator cmp;
+    public final IModificationOperationCallback modificationCallback;
+    public final ISearchOperationCallback searchCallback;
 
     public LSMBTreeOpContext(BTree memBTree, ITreeIndexFrameFactory insertLeafFrameFactory,
-            ITreeIndexFrameFactory deleteLeafFrameFactory) {
+            ITreeIndexFrameFactory deleteLeafFrameFactory, IModificationOperationCallback modificationCallback,
+            ISearchOperationCallback searchCallback) {
         this.cmp = MultiComparator.create(memBTree.getComparatorFactories());
         this.memBTree = memBTree;
         this.insertLeafFrameFactory = insertLeafFrameFactory;
@@ -50,6 +54,8 @@
         if (deleteLeafFrame != null) {
             deleteLeafFrame.setMultiComparator(cmp);
         }
+        this.modificationCallback = modificationCallback;
+        this.searchCallback = searchCallback;
     }
 
     @Override
@@ -81,8 +87,7 @@
 
     private void setMemBTreeAccessor() {
         if (memBTreeAccessor == null) {
-            memBTreeAccessor = (BTree.BTreeAccessor) memBTree.createAccessor(NoOpOperationCallback.INSTANCE,
-                    NoOpOperationCallback.INSTANCE);
+            memBTreeAccessor = (BTree.BTreeAccessor) memBTree.createAccessor(modificationCallback, searchCallback);
             memBTreeOpCtx = memBTreeAccessor.getOpContext();
         }
     }
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
index a5e799f..8cead2a 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
@@ -21,6 +21,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexOpContext;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
+import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOp;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.rtree.api.IRTreeInteriorFrame;
@@ -35,7 +36,7 @@
     public final RTree.RTreeAccessor memRTreeAccessor;
     public final BTree.BTreeAccessor memBTreeAccessor;
     private IndexOp op;
-    
+
     public LSMRTreeOpContext(RTree.RTreeAccessor memRtreeAccessor, IRTreeLeafFrame rtreeLeafFrame,
             IRTreeInteriorFrame rtreeInteriorFrame, ITreeIndexMetaDataFrame rtreeMetaFrame, int rTreeHeightHint,
             BTree.BTreeAccessor memBtreeAccessor, ITreeIndexFrameFactory btreeLeafFrameFactory,
@@ -43,9 +44,10 @@
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories) {
         this.memRTreeAccessor = memRtreeAccessor;
         this.memBTreeAccessor = memBtreeAccessor;
-        this.rtreeOpContext = new RTreeOpContext(rtreeLeafFrame, rtreeInteriorFrame, rtreeMetaFrame, rtreeCmpFactories, rTreeHeightHint);
+        this.rtreeOpContext = new RTreeOpContext(rtreeLeafFrame, rtreeInteriorFrame, rtreeMetaFrame, rtreeCmpFactories,
+                rTreeHeightHint);
         this.btreeOpContext = new BTreeOpContext(btreeLeafFrameFactory, btreeInteriorFrameFactory, btreeMetaFrame,
-        		btreeCmpFactories);
+                btreeCmpFactories, NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
     }
 
     public void reset(IndexOp newOp) {
@@ -63,10 +65,10 @@
     }
 
     public IndexOp getIndexOp() {
-    	return op;
+        return op;
     }
-    
+
     public MultiComparator getBTreeMultiComparator() {
-    	return btreeOpContext.cmp;
+        return btreeOpContext.cmp;
     }
 }
\ No newline at end of file