diff --git a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/ophelpers/IndexOperation.java b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/ophelpers/IndexOperation.java
index 91207e8..b5c0a1d 100644
--- a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/ophelpers/IndexOperation.java
+++ b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/ophelpers/IndexOperation.java
@@ -25,5 +25,6 @@
     PHYSICALDELETE,
     NOOP,
     MERGE,
+    FULL_MERGE,
     FLUSH
 }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
index e9327c6..4330313 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
@@ -245,18 +245,18 @@
         int cmc = currentMutableComponentId.get();
         ctx.setCurrentMutableComponentId(cmc);
         int numMutableComponents = memoryComponents.size();
+        operationalComponents.clear();
         switch (ctx.getOperation()) {
             case UPDATE:
             case UPSERT:
             case PHYSICALDELETE:
             case FLUSH:
             case DELETE:
-                operationalComponents.clear();
                 operationalComponents.add(memoryComponents.get(cmc));
                 break;
             case SEARCH:
             case INSERT:
-                operationalComponents.clear();
+
                 for (int i = 0; i < numMutableComponents - 1; i++) {
                     ILSMComponent c = memoryComponents.get((cmc + i + 1) % numMutableComponents);
                     LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) c;
@@ -270,7 +270,10 @@
                 operationalComponents.addAll(immutableComponents);
                 break;
             case MERGE:
-                // The merger is responsible of choosing and adding the components that are targeted for the merge operation.
+                operationalComponents.addAll(ctx.getComponentsToBeMerged());
+                break;
+            case FULL_MERGE:
+                operationalComponents.addAll(immutableComponents);
                 break;
             default:
                 throw new UnsupportedOperationException("Operation " + ctx.getOperation() + " not supported.");
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
index 6d2d7c0..cb7bae7 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
@@ -48,6 +48,7 @@
     public final IModificationOperationCallback modificationCallback;
     public final ISearchOperationCallback searchCallback;
     private final List<ILSMComponent> componentHolder;
+    private final List<ILSMComponent> componentsToBeMerged;
 
     public LSMBTreeOpContext(List<ILSMComponent> mutableComponents, ITreeIndexFrameFactory insertLeafFrameFactory,
             ITreeIndexFrameFactory deleteLeafFrameFactory, IModificationOperationCallback modificationCallback,
@@ -84,6 +85,7 @@
             deleteLeafFrame.setMultiComparator(cmp);
         }
         this.componentHolder = new LinkedList<ILSMComponent>();
+        this.componentsToBeMerged = new LinkedList<ILSMComponent>();
         this.modificationCallback = modificationCallback;
         this.searchCallback = searchCallback;
     }
@@ -107,6 +109,7 @@
     @Override
     public void reset() {
         componentHolder.clear();
+        componentsToBeMerged.clear();
     }
 
     public IndexOperation getOperation() {
@@ -153,4 +156,9 @@
                 break;
         }
     }
+
+    @Override
+    public List<ILSMComponent> getComponentsToBeMerged() {
+        return componentsToBeMerged;
+    }
 }
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
index bc7cbf7..1903998 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
@@ -37,6 +37,9 @@
     public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException, IndexException;
 
+    public void scheduleFullMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+            throws HyracksDataException, IndexException;
+
     public void merge(ILSMIndexOperationContext ctx, ILSMIOOperation operation) throws HyracksDataException,
             IndexException;
 
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java
index fd7b82f..36a2ca1 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java
@@ -35,6 +35,8 @@
     public void scheduleMerge(ILSMIOOperationCallback callback, List<ILSMComponent> components)
             throws HyracksDataException, IndexException;
 
+    public void scheduleFullMerge(ILSMIOOperationCallback callback) throws HyracksDataException, IndexException;
+
     /**
      * Deletes the tuple from the memory component only.
      * 
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexOperationContext.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexOperationContext.java
index fcd4037..80264bc 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexOperationContext.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexOperationContext.java
@@ -22,6 +22,8 @@
 
 public interface ILSMIndexOperationContext extends IIndexOperationContext {
     public List<ILSMComponent> getComponentHolder();
+    
+    public List<ILSMComponent> getComponentsToBeMerged();
 
     public ISearchOperationCallback getSearchOperationCallback();
 
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java
index 1473071..ebd7020 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java
@@ -19,5 +19,6 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 
 public interface ILSMMergePolicy {
-    public void diskComponentAdded(ILSMIndex index) throws HyracksDataException, IndexException;
+    public void diskComponentAdded(ILSMIndex index, boolean fullMergeIsRequested) throws HyracksDataException,
+            IndexException;
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexCompactOperatorNodePushable.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexCompactOperatorNodePushable.java
new file mode 100644
index 0000000..a61dec4
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexCompactOperatorNodePushable.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2009-2013 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.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+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;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoOpIOOperationCallback;
+
+public class LSMIndexCompactOperatorNodePushable extends AbstractOperatorNodePushable {
+    private final IIndexDataflowHelper indexHelper;
+
+    public LSMIndexCompactOperatorNodePushable(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition) {
+        this.indexHelper = opDesc.getIndexDataflowHelperFactory().createIndexDataflowHelper(opDesc, ctx, partition);
+    }
+
+    @Override
+    public void deinitialize() throws HyracksDataException {
+        indexHelper.close();
+    }
+
+    @Override
+    public int getInputArity() {
+        return 0;
+    }
+
+    @Override
+    public IFrameWriter getInputFrameWriter(int index) {
+        return null;
+    }
+
+    @Override
+    public void initialize() throws HyracksDataException {
+        indexHelper.open();
+        ILSMIndex index = (ILSMIndex) indexHelper.getIndexInstance();
+        ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
+                NoOpOperationCallback.INSTANCE);
+        try {
+            accessor.scheduleFullMerge(NoOpIOOperationCallback.INSTANCE);
+        } catch (Exception e) {
+            indexHelper.close();
+            throw new HyracksDataException(e);
+        }
+    }
+
+    @Override
+    public void setOutputFrameWriter(int index, IFrameWriter writer, RecordDescriptor recordDesc) {
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMTreeIndexCompactOperatorDescriptor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMTreeIndexCompactOperatorDescriptor.java
new file mode 100644
index 0000000..3c40f94
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMTreeIndexCompactOperatorDescriptor.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2009-2013 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.api.dataflow.IOperatorNodePushable;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
+import edu.uci.ics.hyracks.api.job.IOperatorDescriptorRegistry;
+import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexLifecycleManagerProvider;
+import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallbackFactory;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.AbstractTreeIndexOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
+import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallbackFactory;
+import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
+import edu.uci.ics.hyracks.storage.common.file.NoOpLocalResourceFactoryProvider;
+
+public class LSMTreeIndexCompactOperatorDescriptor extends AbstractTreeIndexOperatorDescriptor {
+
+    private static final long serialVersionUID = 1L;
+
+    public LSMTreeIndexCompactOperatorDescriptor(IOperatorDescriptorRegistry spec,
+            IStorageManagerInterface storageManager, IIndexLifecycleManagerProvider lifecycleManagerProvider,
+            IFileSplitProvider fileSplitProvider, ITypeTraits[] typeTraits,
+            IBinaryComparatorFactory[] comparatorFactories, int[] bloomFilterKeyFields,
+            IIndexDataflowHelperFactory dataflowHelperFactory,
+            IModificationOperationCallbackFactory modificationOpCallbackProvider) {
+        super(spec, 0, 0, null, storageManager, lifecycleManagerProvider, fileSplitProvider, typeTraits,
+                comparatorFactories, bloomFilterKeyFields, dataflowHelperFactory, null, false,
+                NoOpLocalResourceFactoryProvider.INSTANCE, NoOpOperationCallbackFactory.INSTANCE,
+                modificationOpCallbackProvider);
+    }
+
+    @Override
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx,
+            IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
+        return new LSMIndexCompactOperatorNodePushable(this, ctx, partition);
+    }
+}
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
index a4af2b7..c90e093 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
@@ -15,13 +15,13 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
 
-import java.util.ArrayList;
 import java.util.List;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent.ComponentState;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
@@ -35,9 +35,19 @@
     }
 
     @Override
-    public void diskComponentAdded(final ILSMIndex index) throws HyracksDataException, IndexException {
-        List<ILSMComponent> immutableComponents = new ArrayList<ILSMComponent>(index.getImmutableComponents());
-        if (immutableComponents.size() >= threshold) {
+    public void diskComponentAdded(final ILSMIndex index, boolean fullMergeIsRequested) throws HyracksDataException,
+            IndexException {
+        List<ILSMComponent> immutableComponents = index.getImmutableComponents();
+        for (ILSMComponent c : immutableComponents) {
+            if (c.getState() != ComponentState.READABLE_UNWRITABLE) {
+                return;
+            }
+        }
+        if (fullMergeIsRequested) {
+            ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
+                    NoOpOperationCallback.INSTANCE);
+            accessor.scheduleFullMerge(NoOpIOOperationCallback.INSTANCE);
+        } else if (immutableComponents.size() >= threshold) {
             ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
                     NoOpOperationCallback.INSTANCE);
             accessor.scheduleMerge(NoOpIOOperationCallback.INSTANCE, immutableComponents);
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
index cd66937..526db2a 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
@@ -16,6 +16,7 @@
 package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
 
 import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -41,11 +42,13 @@
     private final ILSMIndexInternal lsmIndex;
     private final ILSMMergePolicy mergePolicy;
     private final ILSMOperationTracker opTracker;
+    private final AtomicBoolean fullMergeIsRequested;
 
     public LSMHarness(ILSMIndexInternal lsmIndex, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker) {
         this.lsmIndex = lsmIndex;
         this.opTracker = opTracker;
         this.mergePolicy = mergePolicy;
+        fullMergeIsRequested = new AtomicBoolean();
     }
 
     private boolean getAndEnterComponents(ILSMIndexOperationContext ctx, LSMOperationType opType, boolean isTryOperation)
@@ -177,14 +180,14 @@
                         // newComponent is null if the flush op. was not performed.
                         if (newComponent != null) {
                             lsmIndex.addComponent(newComponent);
-                            mergePolicy.diskComponentAdded(lsmIndex);
+                            mergePolicy.diskComponentAdded(lsmIndex, false);
                         }
                         break;
                     case MERGE:
                         // newComponent is null if the merge op. was not performed.
                         if (newComponent != null) {
                             lsmIndex.subsumeMergedComponents(newComponent, ctx.getComponentHolder());
-                            mergePolicy.diskComponentAdded(lsmIndex);
+                            mergePolicy.diskComponentAdded(lsmIndex, fullMergeIsRequested.get());
                         }
                         break;
                     default:
@@ -288,7 +291,6 @@
     @Override
     public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException, IndexException {
-        // Merge should always be a try operation, because it should never fail to enter the components unless the merge policy is erroneous.
         if (!getAndEnterComponents(ctx, LSMOperationType.MERGE, true)) {
             callback.beforeOperation();
             callback.afterOperation(null, null);
@@ -299,6 +301,22 @@
     }
 
     @Override
+    public void scheduleFullMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+            throws HyracksDataException, IndexException {
+        fullMergeIsRequested.set(true);
+        if (!getAndEnterComponents(ctx, LSMOperationType.MERGE, true)) {
+            // If the merge cannot be scheduled because there is already an ongoing merge on subset/all of the components, then
+            // whenever the current merge has finished, it will schedule the full merge again.
+            callback.beforeOperation();
+            callback.afterOperation(null, null);
+            callback.afterFinalize(null);
+            return;
+        }
+        fullMergeIsRequested.set(false);
+        lsmIndex.scheduleMerge(ctx, callback);
+    }
+
+    @Override
     public void merge(ILSMIndexOperationContext ctx, ILSMIOOperation operation) throws HyracksDataException,
             IndexException {
         if (LOGGER.isLoggable(Level.INFO)) {
@@ -324,7 +342,7 @@
     public void addBulkLoadedComponent(ILSMComponent c) throws HyracksDataException, IndexException {
         lsmIndex.markAsValid(c);
         lsmIndex.addComponent(c);
-        mergePolicy.diskComponentAdded(lsmIndex);
+        mergePolicy.diskComponentAdded(lsmIndex, false);
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java
index b0c87f1..c828bd2 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java
@@ -122,12 +122,18 @@
     public void scheduleMerge(ILSMIOOperationCallback callback, List<ILSMComponent> components)
             throws HyracksDataException, IndexException {
         ctx.setOperation(IndexOperation.MERGE);
-        ctx.getComponentHolder().clear();
-        ctx.getComponentHolder().addAll(components);
+        ctx.getComponentsToBeMerged().clear();
+        ctx.getComponentsToBeMerged().addAll(components);
         lsmHarness.scheduleMerge(ctx, callback);
     }
 
     @Override
+    public void scheduleFullMerge(ILSMIOOperationCallback callback) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.FULL_MERGE);
+        lsmHarness.scheduleFullMerge(ctx, callback);
+    }
+
+    @Override
     public void forcePhysicalDelete(ITupleReference tuple) throws HyracksDataException, IndexException {
         ctx.setOperation(IndexOperation.PHYSICALDELETE);
         lsmHarness.forceModify(ctx, tuple);
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoMergePolicy.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoMergePolicy.java
index 17d1b17..02bae37 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoMergePolicy.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoMergePolicy.java
@@ -21,7 +21,7 @@
     INSTANCE;
 
     @Override
-    public void diskComponentAdded(ILSMIndex index) {
+    public void diskComponentAdded(ILSMIndex index, boolean fullMergeIsRequested) {
         // Do nothing
     }
 
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexCompactOperator.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexCompactOperator.java
new file mode 100644
index 0000000..22e7505
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexCompactOperator.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2009-2013 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.dataflow.IOperatorNodePushable;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
+import edu.uci.ics.hyracks.api.job.IOperatorDescriptorRegistry;
+import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexLifecycleManagerProvider;
+import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallbackFactory;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
+import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallbackFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.LSMIndexCompactOperatorNodePushable;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizerFactory;
+import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
+import edu.uci.ics.hyracks.storage.common.file.NoOpLocalResourceFactoryProvider;
+
+public class LSMInvertedIndexCompactOperator extends AbstractLSMInvertedIndexOperatorDescriptor {
+
+    private static final long serialVersionUID = 1L;
+
+    public LSMInvertedIndexCompactOperator(IOperatorDescriptorRegistry spec, IStorageManagerInterface storageManager,
+            IFileSplitProvider fileSplitProvider, IIndexLifecycleManagerProvider lifecycleManagerProvider,
+            ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenComparatorFactories,
+            ITypeTraits[] invListsTypeTraits, IBinaryComparatorFactory[] invListComparatorFactories,
+            IBinaryTokenizerFactory tokenizerFactory, IIndexDataflowHelperFactory dataflowHelperFactory,
+            IModificationOperationCallbackFactory modificationOpCallbackFactory) {
+        super(spec, 1, 1, null, storageManager, fileSplitProvider, lifecycleManagerProvider, tokenTypeTraits,
+                tokenComparatorFactories, invListsTypeTraits, invListComparatorFactories, tokenizerFactory,
+                dataflowHelperFactory, null, false, NoOpLocalResourceFactoryProvider.INSTANCE,
+                NoOpOperationCallbackFactory.INSTANCE, modificationOpCallbackFactory);
+    }
+
+    @Override
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx,
+            IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
+        return new LSMIndexCompactOperatorNodePushable(this, ctx, partition);
+    }
+}
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
index 59200aa..3f50c87 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
@@ -271,15 +271,14 @@
         int cmc = currentMutableComponentId.get();
         ctx.setCurrentMutableComponentId(cmc);
         int numMutableComponents = memoryComponents.size();
+        operationalComponents.clear();
         switch (ctx.getOperation()) {
             case FLUSH:
             case DELETE:
             case INSERT:
-                operationalComponents.clear();
                 operationalComponents.add(memoryComponents.get(cmc));
                 break;
             case SEARCH:
-                operationalComponents.clear();
                 for (int i = 0; i < numMutableComponents - 1; i++) {
                     ILSMComponent c = memoryComponents.get((cmc + i + 1) % numMutableComponents);
                     LSMInvertedIndexMemoryComponent mutableComponent = (LSMInvertedIndexMemoryComponent) c;
@@ -293,8 +292,10 @@
                 operationalComponents.addAll(immutableComponents);
                 break;
             case MERGE:
-                // The merger is responsible of choosing and adding the components that are targeted for the merge operation.
+                operationalComponents.addAll(ctx.getComponentsToBeMerged());
                 break;
+            case FULL_MERGE:
+                operationalComponents.addAll(immutableComponents);
             default:
                 throw new UnsupportedOperationException("Operation " + ctx.getOperation() + " not supported.");
         }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java
index 1d4a313..7e34dfe 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java
@@ -90,12 +90,18 @@
     public void scheduleMerge(ILSMIOOperationCallback callback, List<ILSMComponent> components)
             throws HyracksDataException, IndexException {
         ctx.setOperation(IndexOperation.MERGE);
-        ctx.getComponentHolder().clear();
-        ctx.getComponentHolder().addAll(components);
+        ctx.getComponentsToBeMerged().clear();
+        ctx.getComponentsToBeMerged().addAll(components);
         lsmHarness.scheduleMerge(ctx, callback);
     }
 
     @Override
+    public void scheduleFullMerge(ILSMIOOperationCallback callback) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.FULL_MERGE);
+        lsmHarness.scheduleFullMerge(ctx, callback);
+    }
+
+    @Override
     public void merge(ILSMIOOperation operation) throws HyracksDataException, IndexException {
         lsmHarness.merge(ctx, operation);
     }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
index 1a9303f..671e3f8 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
@@ -35,7 +35,8 @@
 
     private IndexOperation op;
     private final List<ILSMComponent> componentHolder;
-
+    private final List<ILSMComponent> componentsToBeMerged;
+    
     public final IModificationOperationCallback modificationCallback;
     public final ISearchOperationCallback searchCallback;
 
@@ -54,6 +55,7 @@
             IModificationOperationCallback modificationCallback, ISearchOperationCallback searchCallback)
             throws HyracksDataException {
         this.componentHolder = new LinkedList<ILSMComponent>();
+        this.componentsToBeMerged = new LinkedList<ILSMComponent>();
         this.modificationCallback = modificationCallback;
         this.searchCallback = searchCallback;
 
@@ -84,6 +86,7 @@
     @Override
     public void reset() {
         componentHolder.clear();
+        componentsToBeMerged.clear();
     }
 
     @Override
@@ -118,4 +121,9 @@
         currentMutableInvIndexAccessors = mutableInvIndexAccessors[currentMutableComponentId];
         currentDeletedKeysBTreeAccessors = deletedKeysBTreeAccessors[currentMutableComponentId];
     }
+    
+    @Override
+    public List<ILSMComponent> getComponentsToBeMerged() {
+        return componentsToBeMerged;
+    }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
index 00a011c..0d9293a 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
@@ -201,15 +201,14 @@
         int cmc = currentMutableComponentId.get();
         ctx.setCurrentMutableComponentId(cmc);
         int numMutableComponents = memoryComponents.size();
+        operationalComponents.clear();
         switch (ctx.getOperation()) {
             case INSERT:
             case DELETE:
             case FLUSH:
-                operationalComponents.clear();
                 operationalComponents.add(memoryComponents.get(cmc));
                 break;
             case SEARCH:
-                operationalComponents.clear();
                 for (int i = 0; i < numMutableComponents - 1; i++) {
                     ILSMComponent c = memoryComponents.get((cmc + i + 1) % numMutableComponents);
                     LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) c;
@@ -223,8 +222,10 @@
                 operationalComponents.addAll(immutableComponents);
                 break;
             case MERGE:
-                // The merger is responsible of choosing and adding the components that are targeted for the merge operation.
+                operationalComponents.addAll(ctx.getComponentsToBeMerged());
                 break;
+            case FULL_MERGE:
+                operationalComponents.addAll(immutableComponents);
             default:
                 throw new UnsupportedOperationException("Operation " + ctx.getOperation() + " not supported.");
         }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
index b94feba..132e55b 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
@@ -48,6 +48,7 @@
 
     private IndexOperation op;
     public final List<ILSMComponent> componentHolder;
+    private final List<ILSMComponent> componentsToBeMerged;
     public final IModificationOperationCallback modificationCallback;
     public final ISearchOperationCallback searchCallback;
 
@@ -76,6 +77,7 @@
         currentRTreeOpContext = rtreeOpContexts[0];
         currentBTreeOpContext = btreeOpContexts[0];
         this.componentHolder = new LinkedList<ILSMComponent>();
+        this.componentsToBeMerged = new LinkedList<ILSMComponent>();
         this.modificationCallback = modificationCallback;
         this.searchCallback = searchCallback;
     }
@@ -101,6 +103,7 @@
     @Override
     public void reset() {
         componentHolder.clear();
+        componentsToBeMerged.clear();
     }
 
     @Override
@@ -126,4 +129,9 @@
     public IModificationOperationCallback getModificationCallback() {
         return modificationCallback;
     }
+    
+    @Override
+    public List<ILSMComponent> getComponentsToBeMerged() {
+        return componentsToBeMerged;
+    }
 }
\ No newline at end of file