diff --git a/hyracks/hyracks-storage-am-lsm-common/pom.xml b/hyracks/hyracks-storage-am-lsm-common/pom.xml
new file mode 100644
index 0000000..ee62131
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/pom.xml
@@ -0,0 +1,47 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <artifactId>hyracks-storage-am-lsm-common</artifactId>
+
+  <parent>
+    <groupId>edu.uci.ics.hyracks</groupId>
+    <artifactId>hyracks</artifactId>
+    <version>0.2.3-SNAPSHOT</version>
+  </parent>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>2.0.2</version>
+        <configuration>
+          <source>1.7</source>
+          <target>1.7</target>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+  <dependencies>
+  	<dependency>
+  		<groupId>edu.uci.ics.hyracks</groupId>
+  		<artifactId>hyracks-storage-am-common</artifactId>
+  		<version>0.2.3-SNAPSHOT</version>
+  		<type>jar</type>
+  		<scope>compile</scope>
+  	</dependency>
+  	<dependency>
+  		<groupId>edu.uci.ics.hyracks</groupId>
+  		<artifactId>hyracks-storage-am-bloomfilter</artifactId>
+  		<version>0.2.3-SNAPSHOT</version>
+  		<type>jar</type>
+  		<scope>compile</scope>
+  	</dependency>
+  	<dependency>
+  		<groupId>edu.uci.ics.hyracks</groupId>
+  		<artifactId>hyracks-storage-am-btree</artifactId>
+  		<version>0.2.3-SNAPSHOT</version>
+  		<type>jar</type>
+  		<scope>compile</scope>
+  	</dependency>  	
+  </dependencies>
+</project>
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IInMemoryBufferCache.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IInMemoryBufferCache.java
new file mode 100644
index 0000000..082ad2f
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IInMemoryBufferCache.java
@@ -0,0 +1,7 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCacheInternal;
+
+public interface IInMemoryBufferCache extends IBufferCacheInternal {
+    public void open();
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMComponent.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMComponent.java
new file mode 100644
index 0000000..fa00f85
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMComponent.java
@@ -0,0 +1,10 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMOperationType;
+
+public interface ILSMComponent {
+    public boolean threadEnter(LSMOperationType opType) throws InterruptedException;
+
+    public void threadExit(LSMOperationType opType, boolean failedOperation) throws HyracksDataException;
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMComponentFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMComponentFactory.java
new file mode 100644
index 0000000..1f3a2b7
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMComponentFactory.java
@@ -0,0 +1,13 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMComponentFileReferences;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+
+public interface ILSMComponentFactory {
+    public ILSMComponent createLSMComponentInstance(LSMComponentFileReferences cfr) throws IndexException,
+            HyracksDataException;
+
+    public IBufferCache getBufferCache();
+}
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
new file mode 100644
index 0000000..04d7fa3
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+
+public interface ILSMHarness {
+
+    public void forceModify(ILSMIndexOperationContext ctx, ITupleReference tuple) throws HyracksDataException,
+            IndexException;
+
+    public boolean modify(ILSMIndexOperationContext ctx, boolean tryOperation, ITupleReference tuple)
+            throws HyracksDataException, IndexException;
+
+    public void noOp(ILSMIndexOperationContext ctx) throws HyracksDataException;
+
+    public void search(ILSMIndexOperationContext ctx, IIndexCursor cursor, ISearchPredicate pred)
+            throws HyracksDataException, IndexException;
+
+    public void endSearch(ILSMIndexOperationContext ctx) throws HyracksDataException;
+
+    public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+            throws HyracksDataException, IndexException;
+
+    public void merge(ILSMIndexOperationContext ctx, ILSMIOOperation operation) throws HyracksDataException,
+            IndexException;
+
+    public void scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+            throws HyracksDataException;
+
+    public void flush(ILSMIndexOperationContext ctx, ILSMIOOperation operation) throws HyracksDataException,
+            IndexException;
+
+    public void addBulkLoadedComponent(ILSMComponent index) throws HyracksDataException, IndexException;
+
+    public ILSMOperationTracker getOperationTracker();
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperation.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperation.java
new file mode 100644
index 0000000..15fdc6e
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperation.java
@@ -0,0 +1,17 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.util.Set;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.IODeviceHandle;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+
+public interface ILSMIOOperation {
+    public Set<IODeviceHandle> getReadDevices();
+
+    public Set<IODeviceHandle> getWriteDevices();
+
+    public void perform() throws HyracksDataException, IndexException;
+
+    public ILSMIOOperationCallback getCallback();
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallback.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallback.java
new file mode 100644
index 0000000..bf12583
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallback.java
@@ -0,0 +1,14 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface ILSMIOOperationCallback {
+    public void beforeOperation() throws HyracksDataException;
+
+    public void afterOperation(List<ILSMComponent> oldComponents, ILSMComponent newComponent)
+            throws HyracksDataException;
+
+    public void afterFinalize(ILSMComponent newComponent) throws HyracksDataException;
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallbackFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallbackFactory.java
new file mode 100644
index 0000000..52361ee
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallbackFactory.java
@@ -0,0 +1,7 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.io.Serializable;
+
+public interface ILSMIOOperationCallbackFactory extends Serializable {
+    public ILSMIOOperationCallback createIOOperationCallback(Object syncObj);
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallbackProvider.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallbackProvider.java
new file mode 100644
index 0000000..b5c9741
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallbackProvider.java
@@ -0,0 +1,5 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+public interface ILSMIOOperationCallbackProvider {
+    public ILSMIOOperationCallback getIOOperationCallback(ILSMIndex index);
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationScheduler.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationScheduler.java
new file mode 100644
index 0000000..6d96562
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationScheduler.java
@@ -0,0 +1,7 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface ILSMIOOperationScheduler {
+    public void scheduleOperation(ILSMIOOperation operation) throws HyracksDataException;
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationSchedulerProvider.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationSchedulerProvider.java
new file mode 100644
index 0000000..9737728
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationSchedulerProvider.java
@@ -0,0 +1,9 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.io.Serializable;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+
+public interface ILSMIOOperationSchedulerProvider extends Serializable {
+    public ILSMIOOperationScheduler getIOScheduler(IHyracksTaskContext ctx);
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
new file mode 100644
index 0000000..cff47bb
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
+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.lsm.common.impls.LSMHarness;
+
+/**
+ * Methods to be implemented by an LSM index, which are called from {@link LSMHarness}.
+ * The implementations of the methods below should be thread agnostic.
+ * Synchronization of LSM operations like updates/searches/flushes/merges are
+ * done by the {@link LSMHarness}. For example, a flush() implementation should only
+ * create and return the new on-disk component, ignoring the fact that
+ * concurrent searches/updates/merges may be ongoing.
+ */
+public interface ILSMIndex extends IIndex {
+    
+    public void deactivate(boolean flushOnExit) throws HyracksDataException;
+
+    public ILSMIndexAccessor createAccessor(IModificationOperationCallback modificationCallback,
+            ISearchOperationCallback searchCallback);
+
+    public boolean getFlushStatus(ILSMIndex index);
+
+    public ILSMOperationTracker getOperationTracker();
+
+    public ILSMIOOperationScheduler getIOScheduler();
+
+    public List<ILSMComponent> getImmutableComponents();
+}
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
new file mode 100644
index 0000000..a85c24b
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java
@@ -0,0 +1,122 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+
+/**
+ * Client handle for performing operations
+ * (insert/delete/update/search/diskorderscan/merge/flush) on an {@link ILSMHarness}.
+ * An {@link ILSMIndexAccessor} is not thread safe, but different {@link ILSMIndexAccessor}s
+ * can concurrently operate on the same {@link ILSMIndex} (i.e., the {@link ILSMIndex} must allow
+ * concurrent operations).
+ */
+public interface ILSMIndexAccessor extends IIndexAccessor {
+    public void scheduleFlush(ILSMIOOperationCallback callback) throws HyracksDataException;
+
+    public void scheduleMerge(ILSMIOOperationCallback callback) throws HyracksDataException, IndexException;
+
+    /**
+     * Deletes the tuple from the memory component only.
+     * 
+     * @throws HyracksDataException
+     * @throws IndexException
+     */
+    public void physicalDelete(ITupleReference tuple) throws HyracksDataException, IndexException;
+
+    /**
+     * Attempts to insert the given tuple.
+     * If the insert would have to wait for a flush to complete, then this method returns false to
+     * allow the caller to avoid potential deadlock situations.
+     * Otherwise, returns true (insert was successful).
+     * 
+     * @param tuple
+     *            Tuple to be inserted.
+     * @throws HyracksDataException
+     *             If the BufferCache throws while un/pinning or un/latching.
+     * @throws IndexException
+     *             If an index-specific constraint is violated, e.g., the key
+     *             already exists.
+     */
+    public boolean tryInsert(ITupleReference tuple) throws HyracksDataException, IndexException;
+
+    /**
+     * Attempts to delete the given tuple.
+     * If the delete would have to wait for a flush to complete, then this method returns false to
+     * allow the caller to avoid potential deadlock situations.
+     * Otherwise, returns true (delete was successful).
+     * 
+     * @param tuple
+     *            Tuple to be deleted.
+     * @throws HyracksDataException
+     *             If the BufferCache throws while un/pinning or un/latching.
+     * @throws IndexException
+     *             If there is no matching tuple in the index.
+     */
+    public boolean tryDelete(ITupleReference tuple) throws HyracksDataException, IndexException;
+
+    /**
+     * Attempts to update the given tuple.
+     * If the update would have to wait for a flush to complete, then this method returns false to
+     * allow the caller to avoid potential deadlock situations.
+     * Otherwise, returns true (update was successful).
+     * 
+     * @param tuple
+     *            Tuple whose match in the index is to be update with the given
+     *            tuples contents.
+     * @throws HyracksDataException
+     *             If the BufferCache throws while un/pinning or un/latching.
+     * @throws IndexException
+     *             If there is no matching tuple in the index.
+     */
+    public boolean tryUpdate(ITupleReference tuple) throws HyracksDataException, IndexException;
+
+    /**
+     * This operation is only supported by indexes with the notion of a unique key.
+     * If tuple's key already exists, then this operation attempts to performs an update.
+     * Otherwise, it attempts to perform an insert.
+     * If the operation would have to wait for a flush to complete, then this method returns false to
+     * allow the caller to avoid potential deadlock situations.
+     * Otherwise, returns true (insert/update was successful).
+     * 
+     * @param tuple
+     *            Tuple to be deleted.
+     * @throws HyracksDataException
+     *             If the BufferCache throws while un/pinning or un/latching.
+     * @throws IndexException
+     *             If there is no matching tuple in the index.
+     */
+    public boolean tryUpsert(ITupleReference tuple) throws HyracksDataException, IndexException;
+
+    public void forcePhysicalDelete(ITupleReference tuple) throws HyracksDataException, IndexException;
+
+    public void forceInsert(ITupleReference tuple) throws HyracksDataException, IndexException;
+
+    public void forceDelete(ITupleReference tuple) throws HyracksDataException, IndexException;
+
+    /**
+     * This method can be used to increase the number of 'active' operations of an index artificially,
+     * without actually modifying the index.
+     * This method does not block and is guaranteed to trigger the {@link ILSMOperationTracker}'s beforeOperation
+     * and afterOperation calls.
+     * 
+     * @throws HyracksDataException
+     */
+    public void noOp() throws HyracksDataException;
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessorInternal.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessorInternal.java
new file mode 100644
index 0000000..8c28d47
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessorInternal.java
@@ -0,0 +1,24 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+
+public interface ILSMIndexAccessorInternal extends ILSMIndexAccessor {
+
+    /**
+     * Force a flush of the in-memory component.
+     * 
+     * @throws HyracksDataException
+     * @throws TreeIndexException
+     */
+    public void flush(ILSMIOOperation operation) throws HyracksDataException, IndexException;
+
+    /**
+     * Merge all on-disk components.
+     * 
+     * @throws HyracksDataException
+     * @throws TreeIndexException
+     */
+    public void merge(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/ILSMIndexFileManager.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexFileManager.java
new file mode 100644
index 0000000..bc922fe
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexFileManager.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.util.Comparator;
+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.lsm.common.impls.LSMComponentFileReferences;
+
+/**
+ * Provides file names for LSM on-disk components. Also cleans up invalid files.
+ * There are separate methods to get file names for merge and flush because we
+ * need to guarantee the correct order of on-disk components (i.e., the
+ * components produced by flush are always newer than those produced by a
+ * merge).
+ */
+public interface ILSMIndexFileManager {
+    public void createDirs();
+
+    public void deleteDirs();
+
+    public LSMComponentFileReferences getRelFlushFileReference();
+
+    public LSMComponentFileReferences getRelMergeFileReference(String firstFileName, String lastFileName)
+            throws HyracksDataException;
+
+    public String getBaseDir();
+
+    // Deletes invalid files, and returns list of valid files from baseDir.
+    // The returned valid files are correctly sorted (based on the recency of data). 
+    public List<LSMComponentFileReferences> cleanupAndGetValidFiles() throws HyracksDataException, IndexException;
+
+    public Comparator<String> getFileNameComparator();
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java
new file mode 100644
index 0000000..e98165b
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexOperationContext;
+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.ISearchPredicate;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+
+public interface ILSMIndexInternal extends ILSMIndex {
+    public ILSMIndexAccessorInternal createAccessor(IModificationOperationCallback modificationCallback,
+            ISearchOperationCallback searchCallback);
+
+    public void modify(IIndexOperationContext ictx, ITupleReference tuple) throws HyracksDataException, IndexException;
+
+    public void search(ILSMIndexOperationContext ictx, IIndexCursor cursor, ISearchPredicate pred)
+            throws HyracksDataException, IndexException;
+
+    public void scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+            throws HyracksDataException;
+
+    public ILSMComponent flush(ILSMIOOperation operation) throws HyracksDataException, IndexException;
+
+    public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+            throws HyracksDataException, IndexException;
+
+    public ILSMComponent merge(List<ILSMComponent> mergedComponents, ILSMIOOperation operation)
+            throws HyracksDataException, IndexException;
+
+    public void addComponent(ILSMComponent index);
+
+    public void subsumeMergedComponents(ILSMComponent newComponent, List<ILSMComponent> mergedComponents);
+
+    /**
+     * Populates the context's component holder with a snapshot of the components involved in the operation.
+     * 
+     * @param ctx
+     *            - the operation's context
+     */
+    public void getOperationalComponents(ILSMIndexOperationContext ctx);
+
+    public IInMemoryFreePageManager getInMemoryFreePageManager();
+
+    public List<ILSMComponent> getImmutableComponents();
+
+    public void markAsValid(ILSMComponent lsmComponent) throws HyracksDataException;
+
+    public void setFlushStatus(ILSMIndex index, boolean needsFlush);
+
+}
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
new file mode 100644
index 0000000..864d0e7
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexOperationContext.java
@@ -0,0 +1,15 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.util.List;
+
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexOperationContext;
+import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
+
+public interface ILSMIndexOperationContext extends IIndexOperationContext {
+    public List<ILSMComponent> getComponentHolder();
+
+    public ISearchOperationCallback getSearchOperationCallback();
+
+    public IModificationOperationCallback getModificationCallback();
+}
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
new file mode 100644
index 0000000..877c6ffd
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+
+public interface ILSMMergePolicy {
+    public void diskComponentAdded(ILSMIndex index, int totalNumDiskComponents) throws HyracksDataException, IndexException;
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicyProvider.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicyProvider.java
new file mode 100644
index 0000000..57a9609
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicyProvider.java
@@ -0,0 +1,9 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.io.Serializable;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+
+public interface ILSMMergePolicyProvider extends Serializable {
+    public ILSMMergePolicy getMergePolicy(IHyracksTaskContext ctx);
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
new file mode 100644
index 0000000..c3f1f3e
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
@@ -0,0 +1,44 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
+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.lsm.common.impls.LSMOperationType;
+
+/**
+ * This interface exposes methods for tracking and setting the status of operations for the purpose
+ * of coordinating flushes/merges in {@link ILSMIndex}.
+ * Note that 'operation' below refers to {@link IIndexAccessor} methods.
+ * 
+ * @author zheilbron
+ */
+public interface ILSMOperationTracker {
+
+    /**
+     * An {@link ILSMIndex} will call this method before an operation enters it,
+     * i.e., before any latches are taken.
+     * If tryOperation is true, and the operation would have to wait for a flush,
+     * then this method does not block and returns false.
+     * Otherwise, this method returns true, and the operation is considered 'active' in the index.
+     */
+    public void beforeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+            IModificationOperationCallback modificationCallback) throws HyracksDataException;
+
+    /**
+     * An {@link ILSMIndex} will call this method after an operation has left the index,
+     * i.e., after all relevant latches have been released.
+     * After this method has been called, the operation is still considered 'active',
+     * until the issuer of the operation declares it completed by calling completeOperation().
+     */
+    public void afterOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+            IModificationOperationCallback modificationCallback) throws HyracksDataException;
+
+    /**
+     * This method must be called by whoever is requesting the index operation through an {@link IIndexAccessor}.
+     * The use of this method indicates that the operation is no longer 'active'
+     * for the purpose of coordinating flushes/merges.
+     */
+    public void completeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+            IModificationOperationCallback modificationCallback) throws HyracksDataException;
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerFactory.java
new file mode 100644
index 0000000..db7ff6c
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerFactory.java
@@ -0,0 +1,7 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.io.Serializable;
+
+public interface ILSMOperationTrackerFactory extends Serializable {
+    public ILSMOperationTracker createOperationTracker(ILSMIndex index);
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMTreeTupleReference.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMTreeTupleReference.java
new file mode 100644
index 0000000..8d82673
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMTreeTupleReference.java
@@ -0,0 +1,22 @@
+/*
+ * 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.common.api;
+
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleReference;
+
+public interface ILSMTreeTupleReference extends ITreeIndexTupleReference {
+    public boolean isAntimatter();
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java b/hyracks/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..ea7c3b4
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
@@ -0,0 +1,58 @@
+/*
+ * 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.ILSMIOOperationCallbackProvider;
+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.ILSMOperationTrackerFactory;
+
+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 ILSMMergePolicy mergePolicy;
+    protected final ILSMIOOperationScheduler ioScheduler;
+    protected final ILSMOperationTrackerFactory opTrackerFactory;
+    protected final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
+
+    public AbstractLSMIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, mergePolicy, opTrackerFactory,
+                ioScheduler, ioOpCallbackProvider);
+    }
+
+    public AbstractLSMIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
+            int memPageSize, int memNumPages, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+        super(opDesc, ctx, partition);
+        this.memPageSize = memPageSize;
+        this.memNumPages = memNumPages;
+        this.mergePolicy = mergePolicy;
+        this.opTrackerFactory = opTrackerFactory;
+        this.ioScheduler = ioScheduler;
+        this.ioOpCallbackProvider = ioOpCallbackProvider;
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java b/hyracks/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..a2f2a11
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
@@ -0,0 +1,44 @@
+/*
+ * 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.ILSMIOOperationCallbackProvider;
+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.ILSMOperationTrackerFactory;
+
+public abstract class AbstractLSMIndexDataflowHelperFactory implements IIndexDataflowHelperFactory {
+    protected static final long serialVersionUID = 1L;
+
+    protected final ILSMMergePolicyProvider mergePolicyProvider;
+    protected final ILSMOperationTrackerFactory opTrackerFactory;
+    protected final ILSMIOOperationSchedulerProvider ioSchedulerProvider;
+    protected final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
+    protected final int memPageSize;
+    protected final int memNumPages;
+
+    public AbstractLSMIndexDataflowHelperFactory(ILSMMergePolicyProvider mergePolicyProvider,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider, int memPageSize, int memNumPages) {
+        this.mergePolicyProvider = mergePolicyProvider;
+        this.opTrackerFactory = opTrackerFactory;
+        this.ioSchedulerProvider = ioSchedulerProvider;
+        this.ioOpCallbackProvider = ioOpCallbackProvider;
+        this.memPageSize = memPageSize;
+        this.memNumPages = memNumPages;
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java
new file mode 100644
index 0000000..baa9648
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java
@@ -0,0 +1,121 @@
+/*
+ * 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 java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
+import edu.uci.ics.hyracks.dataflow.common.comm.util.FrameUtils;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexInsertUpdateDeleteOperatorNodePushable;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
+
+public class LSMIndexInsertUpdateDeleteOperatorNodePushable extends IndexInsertUpdateDeleteOperatorNodePushable {
+
+    protected FrameTupleAppender appender;
+
+    public LSMIndexInsertUpdateDeleteOperatorNodePushable(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
+            int partition, int[] fieldPermutation, IRecordDescriptorProvider recordDescProvider, IndexOperation op) {
+        super(opDesc, ctx, partition, fieldPermutation, recordDescProvider, op);
+    }
+
+    @Override
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        accessor.reset(buffer);
+        ILSMIndexAccessor lsmAccessor = (ILSMIndexAccessor) indexAccessor;
+        int lastFlushedTupleIndex = 0;
+        int tupleCount = accessor.getTupleCount();
+        for (int i = 0; i < tupleCount; i++) {
+            try {
+                if (tupleFilter != null) {
+                    frameTuple.reset(accessor, i);
+                    if (!tupleFilter.accept(frameTuple)) {
+                        lsmAccessor.noOp();
+                        continue;
+                    }
+                }
+                tuple.reset(accessor, i);
+
+                switch (op) {
+                    case INSERT: {
+                        if (!lsmAccessor.tryInsert(tuple)) {
+                            flushPartialFrame(lastFlushedTupleIndex, i);
+                            lastFlushedTupleIndex = (i == 0) ? 0 : i - 1;
+                            lsmAccessor.insert(tuple);
+                        }
+                        break;
+                    }
+                    case DELETE: {
+                        if (!lsmAccessor.tryDelete(tuple)) {
+                            flushPartialFrame(lastFlushedTupleIndex, i);
+                            lastFlushedTupleIndex = (i == 0) ? 0 : i - 1;
+                            lsmAccessor.delete(tuple);
+                        }
+                        break;
+                    }
+                    case UPSERT: {
+                        if (!lsmAccessor.tryUpsert(tuple)) {
+                            flushPartialFrame(lastFlushedTupleIndex, i);
+                            lastFlushedTupleIndex = (i == 0) ? 0 : i - 1;
+                            lsmAccessor.upsert(tuple);
+                        }
+                        break;
+                    }
+                    case UPDATE: {
+                        if (!lsmAccessor.tryUpdate(tuple)) {
+                            flushPartialFrame(lastFlushedTupleIndex, i);
+                            lastFlushedTupleIndex = (i == 0) ? 0 : i - 1;
+                            lsmAccessor.update(tuple);
+                        }
+                        break;
+                    }
+                    default: {
+                        throw new HyracksDataException("Unsupported operation " + op
+                                + " in tree index InsertUpdateDelete operator");
+                    }
+                }
+            } catch (HyracksDataException e) {
+                throw e;
+            } catch (Exception e) {
+                throw new HyracksDataException(e);
+            }
+        }
+        if (lastFlushedTupleIndex == 0) {
+            // No partial flushing was necessary. Forward entire frame.
+            System.arraycopy(buffer.array(), 0, writeBuffer.array(), 0, buffer.capacity());
+            FrameUtils.flushFrame(writeBuffer, writer);
+        } else {
+            // Flush remaining partial frame.
+            flushPartialFrame(lastFlushedTupleIndex, tupleCount);
+        }
+    }
+
+    private void flushPartialFrame(int startTupleIndex, int endTupleIndex) throws HyracksDataException {
+        if (appender == null) {
+            appender = new FrameTupleAppender(ctx.getFrameSize());
+        }
+        appender.reset(writeBuffer, true);
+        for (int i = startTupleIndex; i < endTupleIndex; i++) {
+            if (!appender.append(accessor, i)) {
+                throw new IllegalStateException("Failed to append tuple into frame.");
+            }
+        }
+        FrameUtils.flushFrame(writeBuffer, writer);
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMTreeIndexInsertUpdateDeleteOperatorDescriptor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMTreeIndexInsertUpdateDeleteOperatorDescriptor.java
new file mode 100644
index 0000000..6297576
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMTreeIndexInsertUpdateDeleteOperatorDescriptor.java
@@ -0,0 +1,63 @@
+/*
+ * 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.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.dataflow.value.RecordDescriptor;
+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.api.ITupleFilterFactory;
+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.am.common.ophelpers.IndexOperation;
+import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
+import edu.uci.ics.hyracks.storage.common.file.NoOpLocalResourceFactoryProvider;
+
+public class LSMTreeIndexInsertUpdateDeleteOperatorDescriptor extends AbstractTreeIndexOperatorDescriptor {
+
+    private static final long serialVersionUID = 1L;
+
+    private final int[] fieldPermutation;
+    private final IndexOperation op;
+
+    public LSMTreeIndexInsertUpdateDeleteOperatorDescriptor(IOperatorDescriptorRegistry spec, RecordDescriptor recDesc,
+            IStorageManagerInterface storageManager, IIndexLifecycleManagerProvider lifecycleManagerProvider,
+            IFileSplitProvider fileSplitProvider, ITypeTraits[] typeTraits,
+            IBinaryComparatorFactory[] comparatorFactories, int[] bloomFilterKeyFields, int[] fieldPermutation,
+            IndexOperation op, IIndexDataflowHelperFactory dataflowHelperFactory,
+            ITupleFilterFactory tupleFilterFactory, IModificationOperationCallbackFactory modificationOpCallbackProvider) {
+        super(spec, 1, 1, recDesc, storageManager, lifecycleManagerProvider, fileSplitProvider, typeTraits,
+                comparatorFactories, bloomFilterKeyFields, dataflowHelperFactory, tupleFilterFactory, false,
+                NoOpLocalResourceFactoryProvider.INSTANCE, NoOpOperationCallbackFactory.INSTANCE,
+                modificationOpCallbackProvider);
+        this.fieldPermutation = fieldPermutation;
+        this.op = op;
+    }
+
+    @Override
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx,
+            IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
+        return new LSMIndexInsertUpdateDeleteOperatorNodePushable(this, ctx, partition, fieldPermutation,
+                recordDescProvider, op);
+    }
+}
\ 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/freepage/DualIndexInMemoryBufferCache.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryBufferCache.java
new file mode 100644
index 0000000..c24c473
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryBufferCache.java
@@ -0,0 +1,63 @@
+/*
+ * 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.common.freepage;
+
+import java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.storage.common.buffercache.ICacheMemoryAllocator;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
+import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
+import edu.uci.ics.hyracks.storage.common.file.TransientFileMapManager;
+
+/**
+ * In-memory buffer cache that supports two tree indexes.
+ * We assume that the tree indexes have 2 fixed pages, one at index 0 (metadata page), and one at index 1 (root page).
+ */
+public class DualIndexInMemoryBufferCache extends InMemoryBufferCache {
+
+    public DualIndexInMemoryBufferCache(ICacheMemoryAllocator allocator, int pageSize, int numPages) {
+        super(allocator, pageSize, numPages, new TransientFileMapManager());
+    }
+
+    @Override
+    public ICachedPage pin(long dpid, boolean newPage) {
+        int pageId = BufferedFileHandle.getPageId(dpid);
+        int fileId = BufferedFileHandle.getFileId(dpid);
+        if (pageId < pages.length) {
+            // Common case: Return regular page.
+            if (pageId == 0 || pageId == 1) {
+                return pages[pageId + 2 * fileId];
+            } else {
+                return pages[pageId];
+            }
+        } else {
+            // Rare case: Return overflow page, possibly expanding overflow
+            // array.
+            synchronized (overflowPages) {
+                int numNewPages = pageId - pages.length - overflowPages.size() + 1;
+                if (numNewPages > 0) {
+                    ByteBuffer[] buffers = allocator.allocate(pageSize, numNewPages);
+                    for (int i = 0; i < numNewPages; i++) {
+                        CachedPage overflowPage = new CachedPage(pages.length + overflowPages.size(), buffers[i]);
+                        overflowPages.add(overflowPage);
+                    }
+                }
+                return overflowPages.get(pageId - pages.length);
+            }
+        }
+    }
+
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryFreePageManager.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryFreePageManager.java
new file mode 100644
index 0000000..7a2be7f
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryFreePageManager.java
@@ -0,0 +1,49 @@
+/*
+ * 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.common.freepage;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
+
+/**
+ * In-memory free page manager that supports two tree indexes.
+ * We assume that the tree indexes have 2 fixed pages, one at index 0 (metadata page), and one at index 1 (root page).
+ */
+public class DualIndexInMemoryFreePageManager extends InMemoryFreePageManager {
+
+    public DualIndexInMemoryFreePageManager(int capacity, ITreeIndexMetaDataFrameFactory metaDataFrameFactory) {
+        super(capacity, metaDataFrameFactory);
+        // We start the currentPageId from 3, because the RTree uses
+        // the first page as metadata page, and the second page as root page.
+        // And the BTree uses the third page as metadata, and the third page as root page 
+        // (when returning free pages we first increment, then get)
+        currentPageId.set(3);
+    }
+
+    @Override
+    public void init(ITreeIndexMetaDataFrame metaFrame, int currentMaxPage) throws HyracksDataException {
+        currentPageId.set(3);
+    }
+
+    public int getCapacity() {
+        return capacity - 4;
+    }
+
+    public void reset() {
+        currentPageId.set(3);
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryBufferCache.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryBufferCache.java
new file mode 100644
index 0000000..66d8ec2
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryBufferCache.java
@@ -0,0 +1,206 @@
+/*
+ * 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.freepage;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICacheMemoryAllocator;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPageInternal;
+import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapManager;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
+
+public class InMemoryBufferCache implements IInMemoryBufferCache {
+    protected final ICacheMemoryAllocator allocator;
+    protected final IFileMapManager fileMapManager;
+    protected final int pageSize;
+    protected final int numPages;
+    protected final List<CachedPage> overflowPages = new ArrayList<CachedPage>();
+    protected CachedPage[] pages;
+
+    public InMemoryBufferCache(ICacheMemoryAllocator allocator, int pageSize, int numPages,
+            IFileMapManager fileMapManager) {
+        this.allocator = allocator;
+        this.fileMapManager = fileMapManager;
+        this.pageSize = pageSize;
+        this.numPages = numPages;
+    }
+
+    public void open() {
+        pages = new CachedPage[numPages];
+        ByteBuffer[] buffers = allocator.allocate(pageSize, numPages);
+        for (int i = 0; i < buffers.length; ++i) {
+            pages[i] = new CachedPage(i, buffers[i]);
+        }
+    }
+
+    @Override
+    public ICachedPage pin(long dpid, boolean newPage) {
+        int pageId = BufferedFileHandle.getPageId(dpid);
+        if (pageId < pages.length) {
+            // Common case: Return regular page.
+            return pages[pageId];
+        } else {
+            // Rare case: Return overflow page, possibly expanding overflow array.
+            synchronized (overflowPages) {
+                int numNewPages = pageId - pages.length - overflowPages.size() + 1;
+                if (numNewPages > 0) {
+                    ByteBuffer[] buffers = allocator.allocate(pageSize, numNewPages);
+                    for (int i = 0; i < numNewPages; i++) {
+                        CachedPage overflowPage = new CachedPage(pages.length + overflowPages.size(), buffers[i]);
+                        overflowPages.add(overflowPage);
+                    }
+                }
+                return overflowPages.get(pageId - pages.length);
+            }
+        }
+    }
+
+    @Override
+    public ICachedPage tryPin(long dpid) throws HyracksDataException {
+        return pin(dpid, false);
+    }
+
+    @Override
+    public int getPageSize() {
+        return pageSize;
+    }
+
+    @Override
+    public int getNumPages() {
+        return numPages;
+    }
+
+    @Override
+    public ICachedPageInternal getPage(int cpid) {
+        return pages[cpid];
+    }
+
+    public int getNumOverflowPages() {
+        return overflowPages.size();
+    }
+
+    @Override
+    public void createFile(FileReference fileRef) throws HyracksDataException {
+        synchronized (fileMapManager) {
+            fileMapManager.registerFile(fileRef);
+        }
+    }
+
+    @Override
+    public void openFile(int fileId) throws HyracksDataException {
+        // Do nothing.
+    }
+
+    @Override
+    public void closeFile(int fileId) throws HyracksDataException {
+        // Do nothing.
+    }
+
+    @Override
+    public void deleteFile(int fileId, boolean flushDirtyPages) throws HyracksDataException {
+        synchronized (fileMapManager) {
+            fileMapManager.unregisterFile(fileId);
+        }
+    }
+
+    @Override
+    public void unpin(ICachedPage page) throws HyracksDataException {
+        // Do Nothing.
+    }
+
+    @Override
+    public void close() {
+        for (int i = 0; i < numPages; ++i) {
+            pages[i] = null;
+        }
+        overflowPages.clear();
+    }
+
+    public class CachedPage implements ICachedPageInternal {
+        private final int cpid;
+        private final ByteBuffer buffer;
+        private final ReadWriteLock latch;
+
+        public CachedPage(int cpid, ByteBuffer buffer) {
+            this.cpid = cpid;
+            this.buffer = buffer;
+            latch = new ReentrantReadWriteLock(true);
+        }
+
+        @Override
+        public ByteBuffer getBuffer() {
+            return buffer;
+        }
+
+        @Override
+        public Object getReplacementStrategyObject() {
+            // Do nothing.
+            return null;
+        }
+
+        @Override
+        public boolean pinIfGoodVictim() {
+            // Do nothing.
+            return false;
+        }
+
+        @Override
+        public int getCachedPageId() {
+            return cpid;
+        }
+
+        @Override
+        public void acquireReadLatch() {
+            latch.readLock().lock();
+        }
+
+        @Override
+        public void acquireWriteLatch() {
+            latch.writeLock().lock();
+        }
+
+        @Override
+        public void releaseReadLatch() {
+            latch.readLock().unlock();
+        }
+
+        @Override
+        public void releaseWriteLatch() {
+            latch.writeLock().unlock();
+        }
+    }
+
+    @Override
+    public void force(int fileId, boolean metadata) throws HyracksDataException {
+    }
+
+    @Override
+    public void flushDirtyPage(ICachedPage page) throws HyracksDataException {
+    }
+
+    public IFileMapProvider getFileMapProvider() {
+        return fileMapManager;
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryFreePageManager.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryFreePageManager.java
new file mode 100644
index 0000000..c601a9b
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryFreePageManager.java
@@ -0,0 +1,112 @@
+/*
+ * 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.freepage;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
+
+public class InMemoryFreePageManager implements IInMemoryFreePageManager {
+    protected final int capacity;
+    protected final AtomicInteger currentPageId = new AtomicInteger();
+    protected final ITreeIndexMetaDataFrameFactory metaDataFrameFactory;
+
+    public InMemoryFreePageManager(int capacity, ITreeIndexMetaDataFrameFactory metaDataFrameFactory) {
+        // We start the currentPageId from 1, because the BTree uses
+        // the first page as metadata page, and the second page as root page.
+        // (when returning free pages we first increment, then get)
+        currentPageId.set(1);
+        this.capacity = capacity;
+        this.metaDataFrameFactory = metaDataFrameFactory;
+    }
+
+    @Override
+    public int getFreePage(ITreeIndexMetaDataFrame metaFrame) throws HyracksDataException {
+        // The very first call returns page id 2 because the BTree uses
+        // the first page as metadata page, and the second page as root page.
+        return currentPageId.incrementAndGet();
+    }
+
+    @Override
+    public int getMaxPage(ITreeIndexMetaDataFrame metaFrame) throws HyracksDataException {
+        return currentPageId.get();
+    }
+
+    @Override
+    public void init(ITreeIndexMetaDataFrame metaFrame, int currentMaxPage) throws HyracksDataException {
+        currentPageId.set(1);
+    }
+
+    @Override
+    public ITreeIndexMetaDataFrameFactory getMetaDataFrameFactory() {
+        return metaDataFrameFactory;
+    }
+
+    public int getCapacity() {
+        return capacity - 2;
+    }
+
+    public void reset() {
+        currentPageId.set(1);
+    }
+
+    public boolean isFull() {
+        return currentPageId.get() >= capacity;
+    }
+
+    @Override
+    public void addFreePage(ITreeIndexMetaDataFrame metaFrame, int freePage) throws HyracksDataException {
+    }
+
+    @Override
+    public byte getMetaPageLevelIndicator() {
+        return 0;
+    }
+
+    @Override
+    public byte getFreePageLevelIndicator() {
+        return 0;
+    }
+
+    @Override
+    public boolean isMetaPage(ITreeIndexMetaDataFrame metaFrame) {
+        return false;
+    }
+
+    @Override
+    public boolean isFreePage(ITreeIndexMetaDataFrame metaFrame) {
+        return false;
+    }
+
+    @Override
+    public int getFirstMetadataPage() {
+        // Method doesn't make sense for this free page manager.
+        return -1;
+    }
+
+    @Override
+    public void open(int fileId) {
+        // Method doesn't make sense for this free page manager.
+    }
+
+    @Override
+    public void close() {
+        // Method doesn't make sense for this free page manager.
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractImmutableLSMComponent.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractImmutableLSMComponent.java
new file mode 100644
index 0000000..b6fc2f7
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractImmutableLSMComponent.java
@@ -0,0 +1,69 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+
+public abstract class AbstractImmutableLSMComponent implements ILSMComponent {
+
+    private ComponentState state;
+    private int readerCount;
+
+    private enum ComponentState {
+        READABLE,
+        READABLE_MERGING,
+        KILLED
+    }
+
+    public AbstractImmutableLSMComponent() {
+        state = ComponentState.READABLE;
+        readerCount = 0;
+    }
+
+    @Override
+    public synchronized boolean threadEnter(LSMOperationType opType) {
+        if (state == ComponentState.KILLED) {
+            return false;
+        }
+
+        switch (opType) {
+            case MODIFICATION:
+            case SEARCH:
+                readerCount++;
+                break;
+            case MERGE:
+                if (state == ComponentState.READABLE_MERGING) {
+                    return false;
+                }
+                state = ComponentState.READABLE_MERGING;
+                readerCount++;
+                break;
+            default:
+                throw new UnsupportedOperationException("Unsupported operation " + opType);
+        }
+        return true;
+    }
+
+    @Override
+    public synchronized void threadExit(LSMOperationType opType, boolean failedOperation) throws HyracksDataException {
+        switch (opType) {
+            case MERGE:
+                if (failedOperation) {
+                    state = ComponentState.READABLE;
+                }
+            case MODIFICATION:
+            case SEARCH:
+                readerCount--;
+
+                if (readerCount == 0 && state == ComponentState.READABLE_MERGING) {
+                    destroy();
+                    state = ComponentState.KILLED;
+                }
+                break;
+            default:
+                throw new UnsupportedOperationException("Unsupported operation " + opType);
+        }
+    }
+
+    protected abstract void destroy() throws HyracksDataException;
+
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
new file mode 100644
index 0000000..0c6b9ab
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
@@ -0,0 +1,194 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicReference;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexInternal;
+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.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
+import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
+
+public abstract class AbstractLSMIndex implements ILSMIndexInternal {
+    protected final static double MAX_BLOOM_FILTER_ACCEPTABLE_FALSE_POSITIVE_RATE = 0.1;
+
+    protected final ILSMHarness lsmHarness;
+
+    protected final ILSMIOOperationScheduler ioScheduler;
+    protected final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
+
+    // In-memory components.   
+    protected final IInMemoryFreePageManager memFreePageManager;
+
+    // On-disk components.    
+    protected final IBufferCache diskBufferCache;
+    protected final ILSMIndexFileManager fileManager;
+    protected final IFileMapProvider diskFileMapProvider;
+    protected final AtomicReference<List<ILSMComponent>> componentsRef;
+
+    protected boolean isActivated;
+
+    private boolean needsFlush = false;
+
+    public AbstractLSMIndex(IInMemoryFreePageManager memFreePageManager, IBufferCache diskBufferCache,
+            ILSMIndexFileManager fileManager, IFileMapProvider diskFileMapProvider, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+        this.memFreePageManager = memFreePageManager;
+        this.diskBufferCache = diskBufferCache;
+        this.diskFileMapProvider = diskFileMapProvider;
+        this.fileManager = fileManager;
+        this.ioScheduler = ioScheduler;
+        this.ioOpCallbackProvider = ioOpCallbackProvider;
+        ILSMOperationTracker opTracker = opTrackerFactory.createOperationTracker(this);
+        lsmHarness = new LSMHarness(this, mergePolicy, opTracker);
+        isActivated = false;
+        componentsRef = new AtomicReference<List<ILSMComponent>>();
+        componentsRef.set(new LinkedList<ILSMComponent>());
+    }
+
+    protected void forceFlushDirtyPages(ITreeIndex treeIndex) throws HyracksDataException {
+        int fileId = treeIndex.getFileId();
+        IBufferCache bufferCache = treeIndex.getBufferCache();
+        // Flush all dirty pages of the tree. 
+        // By default, metadata and data are flushed asynchronously in the buffercache.
+        // This means that the flush issues writes to the OS, but the data may still lie in filesystem buffers.
+        ITreeIndexMetaDataFrame metadataFrame = treeIndex.getFreePageManager().getMetaDataFrameFactory().createFrame();
+        int startPage = 0;
+        int maxPage = treeIndex.getFreePageManager().getMaxPage(metadataFrame);
+        forceFlushDirtyPages(bufferCache, fileId, startPage, maxPage);
+    }
+
+    protected void forceFlushDirtyPages(IBufferCache bufferCache, int fileId, int startPageId, int endPageId)
+            throws HyracksDataException {
+        for (int i = startPageId; i <= endPageId; i++) {
+            ICachedPage page = bufferCache.tryPin(BufferedFileHandle.getDiskPageId(fileId, i));
+            // If tryPin returns null, it means the page is not cached, and therefore cannot be dirty.
+            if (page == null) {
+                continue;
+            }
+            try {
+                bufferCache.flushDirtyPage(page);
+            } finally {
+                bufferCache.unpin(page);
+            }
+        }
+        // Forces all pages of given file to disk. This guarantees the data makes it to disk.
+        bufferCache.force(fileId, true);
+    }
+
+    protected void markAsValidInternal(ITreeIndex treeIndex) throws HyracksDataException {
+        int fileId = treeIndex.getFileId();
+        IBufferCache bufferCache = treeIndex.getBufferCache();
+        ITreeIndexMetaDataFrame metadataFrame = treeIndex.getFreePageManager().getMetaDataFrameFactory().createFrame();
+        // Mark the component as a valid component by flushing the metadata page to disk
+        int metadataPageId = treeIndex.getFreePageManager().getFirstMetadataPage();
+        ICachedPage metadataPage = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, metadataPageId), false);
+        metadataPage.acquireWriteLatch();
+        try {
+            metadataFrame.setPage(metadataPage);
+            metadataFrame.setValid(true);
+
+            // Flush the single modified page to disk.
+            bufferCache.flushDirtyPage(metadataPage);
+
+            // Force modified metadata page to disk.
+            bufferCache.force(fileId, true);
+        } finally {
+            metadataPage.releaseWriteLatch();
+            bufferCache.unpin(metadataPage);
+        }
+    }
+
+    @Override
+    public void addComponent(ILSMComponent c) {
+        List<ILSMComponent> oldList = componentsRef.get();
+        List<ILSMComponent> newList = new ArrayList<ILSMComponent>();
+        newList.add(c);
+        for (ILSMComponent oc : oldList) {
+            newList.add(oc);
+        }
+        componentsRef.set(newList);
+    }
+
+    @Override
+    public void subsumeMergedComponents(ILSMComponent newComponent, List<ILSMComponent> mergedComponents) {
+        List<ILSMComponent> oldList = componentsRef.get();
+        List<ILSMComponent> newList = new ArrayList<ILSMComponent>();
+        int swapIndex = oldList.indexOf(mergedComponents.get(0));
+        int swapSize = mergedComponents.size();
+        for (int i = 0; i < oldList.size(); i++) {
+            if (i < swapIndex || i >= swapIndex + swapSize) {
+                newList.add(oldList.get(i));
+            } else if (i == swapIndex) {
+                newList.add(newComponent);
+            }
+        }
+        componentsRef.set(newList);
+    }
+
+    @Override
+    public IInMemoryFreePageManager getInMemoryFreePageManager() {
+        return memFreePageManager;
+    }
+
+    @Override
+    public List<ILSMComponent> getImmutableComponents() {
+        return componentsRef.get();
+    }
+
+    @Override
+    public void setFlushStatus(ILSMIndex index, boolean needsFlush) {
+        this.needsFlush = needsFlush;
+    }
+
+    @Override
+    public boolean getFlushStatus(ILSMIndex index) {
+        return needsFlush;
+    }
+
+    @Override
+    public ILSMOperationTracker getOperationTracker() {
+        return lsmHarness.getOperationTracker();
+    }
+
+    @Override
+    public ILSMIOOperationScheduler getIOScheduler() {
+        return ioScheduler;
+    }
+
+    @Override
+    public IBufferCache getBufferCache() {
+        return diskBufferCache;
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndexFileManager.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndexFileManager.java
new file mode 100644
index 0000000..a84f8c9
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndexFileManager.java
@@ -0,0 +1,295 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.io.File;
+import java.io.FilenameFilter;
+import java.text.Format;
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Date;
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.api.io.IIOManager;
+import edu.uci.ics.hyracks.api.io.IODeviceHandle;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
+import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
+
+public abstract class AbstractLSMIndexFileManager implements ILSMIndexFileManager {
+
+    protected static final String SPLIT_STRING = "_";
+    protected static final String BLOOM_FILTER_STRING = "f";
+
+    // Use all IODevices registered in ioManager in a round-robin fashion to choose
+    // where to flush and merge
+    protected final IIOManager ioManager;
+    protected final IFileMapProvider fileMapProvider;
+
+    // baseDir should reflect dataset name and partition name.
+    protected String baseDir;
+    protected final Format formatter = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss-SSS");
+    protected final Comparator<String> cmp = new FileNameComparator();
+    protected final Comparator<ComparableFileName> recencyCmp = new RecencyComparator();
+
+    protected final TreeIndexFactory<? extends ITreeIndex> treeFactory;
+
+    // The current index for the round-robin file assignment
+    private int ioDeviceIndex = 0;
+
+    public AbstractLSMIndexFileManager(IIOManager ioManager, IFileMapProvider fileMapProvider, FileReference file,
+            TreeIndexFactory<? extends ITreeIndex> treeFactory, int startIODeviceIndex) {
+        this.baseDir = file.getFile().getPath();
+        if (!baseDir.endsWith(System.getProperty("file.separator"))) {
+            baseDir += System.getProperty("file.separator");
+        }
+        this.fileMapProvider = fileMapProvider;
+        this.ioManager = ioManager;
+        this.treeFactory = treeFactory;
+        ioDeviceIndex = startIODeviceIndex % ioManager.getIODevices().size();
+    }
+
+    private static FilenameFilter fileNameFilter = new FilenameFilter() {
+        public boolean accept(File dir, String name) {
+            return !name.startsWith(".");
+        }
+    };
+
+    protected boolean isValidTreeIndex(ITreeIndex treeIndex) throws HyracksDataException {
+        IBufferCache bufferCache = treeIndex.getBufferCache();
+        treeIndex.activate();
+        try {
+            int metadataPage = treeIndex.getFreePageManager().getFirstMetadataPage();
+            ITreeIndexMetaDataFrame metadataFrame = treeIndex.getFreePageManager().getMetaDataFrameFactory()
+                    .createFrame();
+            ICachedPage page = bufferCache.pin(BufferedFileHandle.getDiskPageId(treeIndex.getFileId(), metadataPage),
+                    false);
+            page.acquireReadLatch();
+            try {
+                metadataFrame.setPage(page);
+                return metadataFrame.isValid();
+            } finally {
+                page.releaseReadLatch();
+                bufferCache.unpin(page);
+            }
+        } finally {
+            treeIndex.deactivate();
+        }
+    }
+
+    protected void cleanupAndGetValidFilesInternal(IODeviceHandle dev, FilenameFilter filter,
+            TreeIndexFactory<? extends ITreeIndex> treeFactory, ArrayList<ComparableFileName> allFiles)
+            throws HyracksDataException, IndexException {
+        File dir = new File(dev.getPath(), baseDir);
+        String[] files = dir.list(filter);
+        for (String fileName : files) {
+            File file = new File(dir.getPath() + File.separator + fileName);
+            FileReference fileRef = new FileReference(file);
+            if (treeFactory == null || isValidTreeIndex(treeFactory.createIndexInstance(fileRef))) {
+                allFiles.add(new ComparableFileName(fileRef));
+            } else {
+                file.delete();
+            }
+        }
+    }
+
+    @Override
+    public void createDirs() {
+        for (IODeviceHandle dev : ioManager.getIODevices()) {
+            File f = new File(dev.getPath(), baseDir);
+            f.mkdirs();
+        }
+    }
+
+    @Override
+    public void deleteDirs() {
+        for (IODeviceHandle dev : ioManager.getIODevices()) {
+            File f = new File(dev.getPath(), baseDir);
+            delete(f);
+        }
+    }
+
+    private void delete(File f) {
+        if (f.isDirectory()) {
+            for (File c : f.listFiles()) {
+                delete(c);
+            }
+        }
+        f.delete();
+    }
+
+    protected static FilenameFilter bloomFilterFilter = new FilenameFilter() {
+        public boolean accept(File dir, String name) {
+            return !name.startsWith(".") && name.endsWith(BLOOM_FILTER_STRING);
+        }
+    };
+
+    protected FileReference createFlushFile(String relFlushFileName) {
+        // Assigns new files to I/O devices in round-robin fashion.
+        IODeviceHandle dev = ioManager.getIODevices().get(ioDeviceIndex);
+        ioDeviceIndex = (ioDeviceIndex + 1) % ioManager.getIODevices().size();
+        return dev.createFileReference(relFlushFileName);
+    }
+
+    protected FileReference createMergeFile(String relMergeFileName) {
+        return createFlushFile(relMergeFileName);
+    }
+
+    @Override
+    public LSMComponentFileReferences getRelFlushFileReference() {
+        Date date = new Date();
+        String ts = formatter.format(date);
+        // Begin timestamp and end timestamp are identical since it is a flush
+        return new LSMComponentFileReferences(createFlushFile(baseDir + ts + SPLIT_STRING + ts), null, null);
+    }
+
+    @Override
+    public LSMComponentFileReferences getRelMergeFileReference(String firstFileName, String lastFileName)
+            throws HyracksDataException {
+        String[] firstTimestampRange = firstFileName.split(SPLIT_STRING);
+        String[] lastTimestampRange = lastFileName.split(SPLIT_STRING);
+        // Get the range of timestamps by taking the earliest and the latest timestamps
+        return new LSMComponentFileReferences(createMergeFile(baseDir + firstTimestampRange[0] + SPLIT_STRING
+                + lastTimestampRange[1]), null, null);
+    }
+
+    @Override
+    public List<LSMComponentFileReferences> cleanupAndGetValidFiles() throws HyracksDataException, IndexException {
+        List<LSMComponentFileReferences> validFiles = new ArrayList<LSMComponentFileReferences>();
+        ArrayList<ComparableFileName> allFiles = new ArrayList<ComparableFileName>();
+
+        // Gather files from all IODeviceHandles and delete invalid files
+        // There are two types of invalid files:
+        // (1) The isValid flag is not set
+        // (2) The file's interval is contained by some other file
+        // Here, we only filter out (1).
+        for (IODeviceHandle dev : ioManager.getIODevices()) {
+            cleanupAndGetValidFilesInternal(dev, fileNameFilter, treeFactory, allFiles);
+        }
+
+        if (allFiles.isEmpty()) {
+            return validFiles;
+        }
+
+        if (allFiles.size() == 1) {
+            validFiles.add(new LSMComponentFileReferences(allFiles.get(0).fileRef, null, null));
+            return validFiles;
+        }
+
+        // Sorts files names from earliest to latest timestamp.
+        Collections.sort(allFiles);
+
+        List<ComparableFileName> validComparableFiles = new ArrayList<ComparableFileName>();
+        ComparableFileName last = allFiles.get(0);
+        validComparableFiles.add(last);
+        for (int i = 1; i < allFiles.size(); i++) {
+            ComparableFileName current = allFiles.get(i);
+            // The current start timestamp is greater than last stop timestamp so current is valid.
+            if (current.interval[0].compareTo(last.interval[1]) > 0) {
+                validComparableFiles.add(current);
+                last = current;
+            } else if (current.interval[0].compareTo(last.interval[0]) >= 0
+                    && current.interval[1].compareTo(last.interval[1]) <= 0) {
+                // The current file is completely contained in the interval of the 
+                // last file. Thus the last file must contain at least as much information 
+                // as the current file, so delete the current file.
+                current.fileRef.delete();
+            } else {
+                // This scenario should not be possible since timestamps are monotonically increasing.
+                throw new HyracksDataException("Found LSM files with overlapping timestamp intervals, "
+                        + "but the intervals were not contained by another file.");
+            }
+        }
+
+        // Sort valid files in reverse lexicographical order, such that newer files come first.
+        Collections.sort(validComparableFiles, recencyCmp);
+        for (ComparableFileName cmpFileName : validComparableFiles) {
+            validFiles.add(new LSMComponentFileReferences(cmpFileName.fileRef, null, null));
+        }
+
+        return validFiles;
+    }
+
+    @Override
+    public Comparator<String> getFileNameComparator() {
+        return cmp;
+    }
+
+    /**
+     * Sorts strings in reverse lexicographical order. The way we construct the
+     * file names above guarantees that:
+     * 1. Flushed files sort lower than merged files
+     * 2. Flushed files are sorted from newest to oldest (based on the timestamp
+     * string)
+     */
+    private class FileNameComparator implements Comparator<String> {
+        @Override
+        public int compare(String a, String b) {
+            // Consciously ignoring locale.
+            return -a.compareTo(b);
+        }
+    }
+
+    @Override
+    public String getBaseDir() {
+        return baseDir;
+    }
+
+    protected class ComparableFileName implements Comparable<ComparableFileName> {
+        public final FileReference fileRef;
+        public final String fullPath;
+        public final String fileName;
+
+        // Timestamp interval.
+        public final String[] interval;
+
+        public ComparableFileName(FileReference fileRef) {
+            this.fileRef = fileRef;
+            this.fullPath = fileRef.getFile().getAbsolutePath();
+            this.fileName = fileRef.getFile().getName();
+            interval = fileName.split(SPLIT_STRING);
+        }
+
+        @Override
+        public int compareTo(ComparableFileName b) {
+            int startCmp = interval[0].compareTo(b.interval[0]);
+            if (startCmp != 0) {
+                return startCmp;
+            }
+            return b.interval[1].compareTo(interval[1]);
+        }
+    }
+
+    private class RecencyComparator implements Comparator<ComparableFileName> {
+        @Override
+        public int compare(ComparableFileName a, ComparableFileName b) {
+            int cmp = -a.interval[0].compareTo(b.interval[0]);
+            if (cmp != 0) {
+                return cmp;
+            }
+            return -a.interval[1].compareTo(b.interval[1]);
+        }
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMutableLSMComponent.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMutableLSMComponent.java
new file mode 100644
index 0000000..1a6636a
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMutableLSMComponent.java
@@ -0,0 +1,104 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+
+public abstract class AbstractMutableLSMComponent implements ILSMComponent {
+
+    private int readerCount;
+    private int writerCount;
+    private ComponentState state;
+
+    private enum ComponentState {
+        READABLE_WRITABLE,
+        READABLE_UNWRITABLE,
+        READABLE_UNWRITABLE_FLUSHING,
+        UNREADABLE_UNWRITABLE
+    }
+
+    public AbstractMutableLSMComponent() {
+        readerCount = 0;
+        writerCount = 0;
+        state = ComponentState.READABLE_WRITABLE;
+    }
+
+    @Override
+    public synchronized boolean threadEnter(LSMOperationType opType) throws InterruptedException {
+        switch (opType) {
+            case FORCE_MODIFICATION:
+                if (state != ComponentState.READABLE_WRITABLE && state != ComponentState.READABLE_UNWRITABLE) {
+                    return false;
+                }
+                writerCount++;
+                break;
+            case MODIFICATION:
+                if (state != ComponentState.READABLE_WRITABLE) {
+                    return false;
+                }
+                writerCount++;
+                break;
+            case SEARCH:
+                if (state == ComponentState.UNREADABLE_UNWRITABLE) {
+                    return false;
+                }
+                readerCount++;
+                break;
+            case FLUSH:
+                if (state == ComponentState.READABLE_UNWRITABLE_FLUSHING
+                        || state == ComponentState.UNREADABLE_UNWRITABLE) {
+                    return false;
+                }
+
+                state = ComponentState.READABLE_UNWRITABLE_FLUSHING;
+                while (writerCount > 0) {
+                    wait();
+                }
+                readerCount++;
+                break;
+            default:
+                throw new UnsupportedOperationException("Unsupported operation " + opType);
+        }
+        return true;
+    }
+
+    @Override
+    public synchronized void threadExit(LSMOperationType opType, boolean failedOperation) throws HyracksDataException {
+        switch (opType) {
+            case FORCE_MODIFICATION:
+            case MODIFICATION:
+                writerCount--;
+                if (state == ComponentState.READABLE_WRITABLE && isFull()) {
+                    state = ComponentState.READABLE_UNWRITABLE;
+                }
+                break;
+            case SEARCH:
+                readerCount--;
+                if (state == ComponentState.UNREADABLE_UNWRITABLE && readerCount == 0) {
+                    reset();
+                    state = ComponentState.READABLE_WRITABLE;
+                } else if (state == ComponentState.READABLE_WRITABLE && isFull()) {
+                    state = ComponentState.READABLE_UNWRITABLE;
+                }
+                break;
+            case FLUSH:
+                if (failedOperation) {
+                    state = isFull() ? ComponentState.READABLE_UNWRITABLE : ComponentState.READABLE_WRITABLE;
+                }
+                readerCount--;
+                if (readerCount == 0) {
+                    reset();
+                    state = ComponentState.READABLE_WRITABLE;
+                } else if (state == ComponentState.READABLE_UNWRITABLE_FLUSHING) {
+                    state = ComponentState.UNREADABLE_UNWRITABLE;
+                }
+                break;
+            default:
+                throw new UnsupportedOperationException("Unsupported operation " + opType);
+        }
+        notifyAll();
+    }
+
+    protected abstract boolean isFull();
+
+    protected abstract void reset() throws HyracksDataException;
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BTreeFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BTreeFactory.java
new file mode 100644
index 0000000..008c418
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BTreeFactory.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
+import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManagerFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
+
+public class BTreeFactory extends TreeIndexFactory<BTree> {
+
+    public BTreeFactory(IBufferCache bufferCache, IFileMapProvider fileMapProvider,
+            IFreePageManagerFactory freePageManagerFactory, ITreeIndexFrameFactory interiorFrameFactory,
+            ITreeIndexFrameFactory leafFrameFactory, IBinaryComparatorFactory[] cmpFactories, int fieldCount) {
+        super(bufferCache, fileMapProvider, freePageManagerFactory, interiorFrameFactory, leafFrameFactory,
+                cmpFactories, fieldCount);
+    }
+
+    @Override
+    public BTree createIndexInstance(FileReference file) throws IndexException {
+        return new BTree(bufferCache, fileMapProvider, freePageManagerFactory.createFreePageManager(),
+                interiorFrameFactory, leafFrameFactory, cmpFactories, fieldCount, file);
+    }
+
+}
\ 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/BlockingIOOperationCallbackWrapper.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BlockingIOOperationCallbackWrapper.java
new file mode 100644
index 0000000..34e1f0d
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BlockingIOOperationCallbackWrapper.java
@@ -0,0 +1,43 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
+
+public class BlockingIOOperationCallbackWrapper implements ILSMIOOperationCallback {
+
+    private boolean notified = false;
+
+    private final ILSMIOOperationCallback wrappedCallback;
+
+    public BlockingIOOperationCallbackWrapper(ILSMIOOperationCallback callback) {
+        this.wrappedCallback = callback;
+    }
+
+    public synchronized void waitForIO() throws InterruptedException {
+        if (!notified) {
+            this.wait();
+        }
+        notified = false;
+    }
+
+    @Override
+    public void beforeOperation() throws HyracksDataException {
+        wrappedCallback.beforeOperation();
+    }
+
+    @Override
+    public void afterOperation(List<ILSMComponent> oldComponents, ILSMComponent newComponent)
+            throws HyracksDataException {
+        wrappedCallback.afterOperation(oldComponents, newComponent);
+    }
+
+    @Override
+    public synchronized void afterFinalize(ILSMComponent newComponent) throws HyracksDataException {
+        wrappedCallback.afterFinalize(newComponent);
+        this.notifyAll();
+        notified = true;
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BloomFilterAwareBTreePointSearchCursor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BloomFilterAwareBTreePointSearchCursor.java
new file mode 100644
index 0000000..af08bdb
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BloomFilterAwareBTreePointSearchCursor.java
@@ -0,0 +1,40 @@
+/*
+ * 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.impls;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilter;
+import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame;
+import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeRangeSearchCursor;
+
+public class BloomFilterAwareBTreePointSearchCursor extends BTreeRangeSearchCursor {
+    private final BloomFilter bloomFilter;
+    private long[] hashes = new long[2];
+
+    public BloomFilterAwareBTreePointSearchCursor(IBTreeLeafFrame frame, boolean exclusiveLatchNodes,
+            BloomFilter bloomFilter) {
+        super(frame, exclusiveLatchNodes);
+        this.bloomFilter = bloomFilter;
+    }
+
+    @Override
+    public boolean hasNext() throws HyracksDataException {
+        if (bloomFilter.contains(lowKey, hashes)) {
+            return super.hasNext();
+        }
+        return false;
+    }
+}
\ 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
new file mode 100644
index 0000000..1c72abf
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
+
+public class ConstantMergePolicy implements ILSMMergePolicy {
+
+    private final int threshold;
+
+    public ConstantMergePolicy(int threshold) {
+        this.threshold = threshold;
+    }
+
+    @Override
+    public void diskComponentAdded(final ILSMIndex index, int totalNumDiskComponents) throws HyracksDataException,
+            IndexException {
+        if (totalNumDiskComponents >= threshold) {
+            ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
+                    NoOpOperationCallback.INSTANCE);
+            accessor.scheduleMerge(NoOpIOOperationCallback.INSTANCE);
+        }
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicyProvider.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicyProvider.java
new file mode 100644
index 0000000..b404c9b
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicyProvider.java
@@ -0,0 +1,22 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
+
+public class ConstantMergePolicyProvider implements ILSMMergePolicyProvider {
+
+    private static final long serialVersionUID = 1L;
+
+    private final int threshold;
+
+    public ConstantMergePolicyProvider(int threshold) {
+        this.threshold = threshold;
+    }
+
+    @Override
+    public ILSMMergePolicy getMergePolicy(IHyracksTaskContext ctx) {
+        return new ConstantMergePolicy(threshold);
+    }
+
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/IndexFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/IndexFactory.java
new file mode 100644
index 0000000..3feaecf
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/IndexFactory.java
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManagerFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
+
+public abstract class IndexFactory<T extends IIndex> {
+
+    protected final IBufferCache bufferCache;
+    protected final IFileMapProvider fileMapProvider;
+    protected final IFreePageManagerFactory freePageManagerFactory;
+
+    public IndexFactory(IBufferCache bufferCache, IFileMapProvider fileMapProvider,
+            IFreePageManagerFactory freePageManagerFactory) {
+        this.bufferCache = bufferCache;
+        this.fileMapProvider = fileMapProvider;
+        this.freePageManagerFactory = freePageManagerFactory;
+    }
+
+    public abstract T createIndexInstance(FileReference file) throws IndexException;
+
+    public IBufferCache getBufferCache() {
+        return bufferCache;
+    }
+}
\ 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/LSMComponentFileReferences.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMComponentFileReferences.java
new file mode 100644
index 0000000..019dca4
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMComponentFileReferences.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.io.FileReference;
+
+public final class LSMComponentFileReferences {
+
+    // The FileReference for the index that is used for inserting records of the component. For instance, this will be the FileReference of the RTree in one component of the LSM-RTree.
+    private final FileReference insertIndexFileReference;
+    // This FileReference for the delete index (if any). For example, this will be the the FileReference of the buddy BTree in one component of the LSM-RTree.
+    private final FileReference deleteIndexFileReference;
+
+    // This FileReference for the bloom filter (if any). 
+    private final FileReference bloomFilterFileReference;
+
+    public LSMComponentFileReferences(FileReference insertIndexFileReference, FileReference deleteIndexFileReference,
+            FileReference bloomFilterFileReference) {
+        this.insertIndexFileReference = insertIndexFileReference;
+        this.deleteIndexFileReference = deleteIndexFileReference;
+        this.bloomFilterFileReference = bloomFilterFileReference;
+    }
+
+    public FileReference getInsertIndexFileReference() {
+        return insertIndexFileReference;
+    }
+
+    public FileReference getDeleteIndexFileReference() {
+        return deleteIndexFileReference;
+    }
+
+    public FileReference getBloomFilterFileReference() {
+        return bloomFilterFileReference;
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMComponentState.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMComponentState.java
new file mode 100644
index 0000000..e554a6e
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMComponentState.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+public enum LSMComponentState {
+    FLUSHING,
+    MERGING,
+    DONE_FLUSHING,
+    DONE_MERGING
+}
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
new file mode 100644
index 0000000..4a140b4
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
@@ -0,0 +1,231 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexInternal;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+
+public class LSMHarness implements ILSMHarness {
+    private final ILSMIndexInternal lsmIndex;
+    private final ILSMMergePolicy mergePolicy;
+    private final ILSMOperationTracker opTracker;
+
+    public LSMHarness(ILSMIndexInternal lsmIndex, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker) {
+        this.lsmIndex = lsmIndex;
+        this.opTracker = opTracker;
+        this.mergePolicy = mergePolicy;
+    }
+
+    private void threadExit(ILSMIndexOperationContext opCtx, LSMOperationType opType) throws HyracksDataException {
+        if (!lsmIndex.getFlushStatus(lsmIndex) && lsmIndex.getInMemoryFreePageManager().isFull()) {
+            lsmIndex.setFlushStatus(lsmIndex, true);
+        }
+        opTracker.afterOperation(opType, opCtx.getSearchOperationCallback(), opCtx.getModificationCallback());
+    }
+
+    private boolean getAndEnterComponents(ILSMIndexOperationContext ctx, LSMOperationType opType, boolean tryOperation)
+            throws HyracksDataException {
+        int numEntered = 0;
+        boolean entranceSuccessful = false;
+        List<ILSMComponent> entered = new ArrayList<ILSMComponent>();
+
+        while (!entranceSuccessful) {
+            entered.clear();
+            lsmIndex.getOperationalComponents(ctx);
+            List<ILSMComponent> components = ctx.getComponentHolder();
+            try {
+                for (ILSMComponent c : components) {
+                    if (!c.threadEnter(opType)) {
+                        break;
+                    }
+                    numEntered++;
+                    entered.add(c);
+                }
+                entranceSuccessful = numEntered == components.size();
+            } catch (InterruptedException e) {
+                entranceSuccessful = false;
+                throw new HyracksDataException(e);
+            } finally {
+                if (!entranceSuccessful) {
+                    for (ILSMComponent c : components) {
+                        if (numEntered <= 0) {
+                            break;
+                        }
+                        c.threadExit(opType, true);
+                        numEntered--;
+                    }
+                }
+            }
+            if (tryOperation && !entranceSuccessful) {
+                return false;
+            }
+        }
+
+        opTracker.beforeOperation(opType, ctx.getSearchOperationCallback(), ctx.getModificationCallback());
+        return true;
+    }
+
+    private void exitComponents(ILSMIndexOperationContext ctx, LSMOperationType opType, boolean failedOperation)
+            throws HyracksDataException {
+        try {
+            for (ILSMComponent c : ctx.getComponentHolder()) {
+                c.threadExit(opType, failedOperation);
+            }
+        } finally {
+            threadExit(ctx, opType);
+        }
+    }
+
+    @Override
+    public void forceModify(ILSMIndexOperationContext ctx, ITupleReference tuple) throws HyracksDataException,
+            IndexException {
+        LSMOperationType opType = LSMOperationType.FORCE_MODIFICATION;
+        modify(ctx, false, tuple, opType);
+    }
+
+    @Override
+    public boolean modify(ILSMIndexOperationContext ctx, boolean tryOperation, ITupleReference tuple)
+            throws HyracksDataException, IndexException {
+        LSMOperationType opType = LSMOperationType.MODIFICATION;
+        return modify(ctx, tryOperation, tuple, opType);
+    }
+
+    private boolean modify(ILSMIndexOperationContext ctx, boolean tryOperation, ITupleReference tuple,
+            LSMOperationType opType) throws HyracksDataException, IndexException {
+        if (!getAndEnterComponents(ctx, opType, tryOperation)) {
+            return false;
+        }
+        try {
+            lsmIndex.modify(ctx, tuple);
+        } finally {
+            exitComponents(ctx, opType, false);
+        }
+
+        return true;
+    }
+
+    @Override
+    public void search(ILSMIndexOperationContext ctx, IIndexCursor cursor, ISearchPredicate pred)
+            throws HyracksDataException, IndexException {
+        LSMOperationType opType = LSMOperationType.SEARCH;
+        getAndEnterComponents(ctx, opType, false);
+        try {
+            lsmIndex.search(ctx, cursor, pred);
+        } catch (HyracksDataException e) {
+            exitComponents(ctx, opType, true);
+            throw e;
+        } catch (IndexException e) {
+            exitComponents(ctx, opType, true);
+            throw e;
+        }
+    }
+
+    @Override
+    public void endSearch(ILSMIndexOperationContext ctx) throws HyracksDataException {
+        if (ctx.getOperation() == IndexOperation.SEARCH) {
+            exitComponents(ctx, LSMOperationType.SEARCH, false);
+        }
+    }
+
+    @Override
+    public void noOp(ILSMIndexOperationContext ctx) throws HyracksDataException {
+        LSMOperationType opType = LSMOperationType.NOOP;
+        opTracker.beforeOperation(opType, ctx.getSearchOperationCallback(), ctx.getModificationCallback());
+        threadExit(ctx, opType);
+    }
+
+    @Override
+    public void scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+            throws HyracksDataException {
+        if (!getAndEnterComponents(ctx, LSMOperationType.FLUSH, true)) {
+            return;
+        }
+        lsmIndex.setFlushStatus(lsmIndex, false);
+        lsmIndex.scheduleFlush(ctx, callback);
+    }
+
+    @Override
+    public void flush(ILSMIndexOperationContext ctx, ILSMIOOperation operation) throws HyracksDataException,
+            IndexException {
+        operation.getCallback().beforeOperation();
+        ILSMComponent newComponent = lsmIndex.flush(operation);
+        operation.getCallback().afterOperation(null, newComponent);
+        lsmIndex.markAsValid(newComponent);
+        operation.getCallback().afterFinalize(newComponent);
+
+        lsmIndex.addComponent(newComponent);
+        int numComponents = lsmIndex.getImmutableComponents().size();
+
+        mergePolicy.diskComponentAdded(lsmIndex, numComponents);
+        exitComponents(ctx, LSMOperationType.FLUSH, false);
+    }
+
+    @Override
+    public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+            throws HyracksDataException, IndexException {
+        LSMOperationType opType = LSMOperationType.MERGE;
+        if (!getAndEnterComponents(ctx, opType, false)) {
+            return;
+        }
+        if (ctx.getComponentHolder().size() > 1) {
+            lsmIndex.scheduleMerge(ctx, callback);
+        } else {
+            exitComponents(ctx, opType, true);
+        }
+    }
+
+    @Override
+    public void merge(ILSMIndexOperationContext ctx, ILSMIOOperation operation) throws HyracksDataException,
+            IndexException {
+        List<ILSMComponent> mergedComponents = new ArrayList<ILSMComponent>();
+        operation.getCallback().beforeOperation();
+        ILSMComponent newComponent = lsmIndex.merge(mergedComponents, operation);
+        ctx.getComponentHolder().addAll(mergedComponents);
+        operation.getCallback().afterOperation(mergedComponents, newComponent);
+        lsmIndex.markAsValid(newComponent);
+        operation.getCallback().afterFinalize(newComponent);
+        lsmIndex.subsumeMergedComponents(newComponent, mergedComponents);
+        exitComponents(ctx, LSMOperationType.MERGE, false);
+    }
+
+    @Override
+    public void addBulkLoadedComponent(ILSMComponent c) throws HyracksDataException, IndexException {
+        lsmIndex.markAsValid(c);
+        lsmIndex.addComponent(c);
+        int numComponents = lsmIndex.getImmutableComponents().size();
+        mergePolicy.diskComponentAdded(lsmIndex, numComponents);
+    }
+
+    @Override
+    public ILSMOperationTracker getOperationTracker() {
+        return opTracker;
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java
new file mode 100644
index 0000000..7f08ba4
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java
@@ -0,0 +1,211 @@
+/*
+ * 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.common.impls;
+
+import java.util.Comparator;
+import java.util.List;
+import java.util.PriorityQueue;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMTreeTupleReference;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
+
+public abstract class LSMIndexSearchCursor implements ITreeIndexCursor {
+    protected PriorityQueueElement outputElement;
+    protected IIndexCursor[] rangeCursors;
+    protected PriorityQueue<PriorityQueueElement> outputPriorityQueue;
+    protected PriorityQueueComparator pqCmp;
+    protected MultiComparator cmp;
+    protected boolean needPush;
+    protected boolean includeMemComponent;
+    protected ILSMHarness lsmHarness;
+    protected final ILSMIndexOperationContext opCtx;
+
+    protected List<ILSMComponent> operationalComponents;
+
+    public LSMIndexSearchCursor(ILSMIndexOperationContext opCtx) {
+        this.opCtx = opCtx;
+        outputElement = null;
+        needPush = false;
+    }
+
+    public void initPriorityQueue() throws HyracksDataException, IndexException {
+        int pqInitSize = (rangeCursors.length > 0) ? rangeCursors.length : 1;
+        outputPriorityQueue = new PriorityQueue<PriorityQueueElement>(pqInitSize, pqCmp);
+        for (int i = 0; i < rangeCursors.length; i++) {
+            pushIntoPriorityQueue(new PriorityQueueElement(i));
+        }
+    }
+
+    public IIndexCursor getCursor(int cursorIndex) {
+        return rangeCursors[cursorIndex];
+    }
+
+    @Override
+    public void reset() throws HyracksDataException, IndexException {
+        outputElement = null;
+        needPush = false;
+
+        if (outputPriorityQueue != null) {
+            outputPriorityQueue.clear();
+        }
+
+        if (rangeCursors != null) {
+            for (int i = 0; i < rangeCursors.length; i++) {
+                rangeCursors[i].reset();
+            }
+        }
+        rangeCursors = null;
+    }
+
+    @Override
+    public boolean hasNext() throws HyracksDataException, IndexException {
+        checkPriorityQueue();
+        return !outputPriorityQueue.isEmpty();
+    }
+
+    @Override
+    public void next() throws HyracksDataException {
+        outputElement = outputPriorityQueue.poll();
+        needPush = true;
+    }
+
+    @Override
+    public ICachedPage getPage() {
+        // do nothing
+        return null;
+    }
+
+    @Override
+    public void close() throws HyracksDataException {
+        if (lsmHarness != null) {
+            try {
+                outputPriorityQueue.clear();
+                for (int i = 0; i < rangeCursors.length; i++) {
+                    rangeCursors[i].close();
+                }
+                rangeCursors = null;
+            } finally {
+                lsmHarness.endSearch(opCtx);
+            }
+        }
+    }
+
+    @Override
+    public void setBufferCache(IBufferCache bufferCache) {
+        // do nothing
+    }
+
+    @Override
+    public void setFileId(int fileId) {
+        // do nothing
+    }
+
+    @Override
+    public ITupleReference getTuple() {
+        return outputElement.getTuple();
+    }
+
+    protected boolean pushIntoPriorityQueue(PriorityQueueElement e) throws HyracksDataException, IndexException {
+        int cursorIndex = e.getCursorIndex();
+        if (rangeCursors[cursorIndex].hasNext()) {
+            rangeCursors[cursorIndex].next();
+            e.reset(rangeCursors[cursorIndex].getTuple());
+            outputPriorityQueue.offer(e);
+            return true;
+        }
+        rangeCursors[cursorIndex].close();
+        return false;
+    }
+
+    protected boolean isDeleted(PriorityQueueElement checkElement) throws HyracksDataException, IndexException {
+        return ((ILSMTreeTupleReference) checkElement.getTuple()).isAntimatter();
+    }
+
+    abstract protected void checkPriorityQueue() throws HyracksDataException, IndexException;
+
+    @Override
+    public boolean exclusiveLatchNodes() {
+        return false;
+    }
+
+    public class PriorityQueueElement {
+        private ITupleReference tuple;
+        private final int cursorIndex;
+
+        public PriorityQueueElement(int cursorIndex) {
+            tuple = null;
+            this.cursorIndex = cursorIndex;
+        }
+
+        public ITupleReference getTuple() {
+            return tuple;
+        }
+
+        public int getCursorIndex() {
+            return cursorIndex;
+        }
+
+        public void reset(ITupleReference tuple) {
+            this.tuple = tuple;
+        }
+    }
+
+    public class PriorityQueueComparator implements Comparator<PriorityQueueElement> {
+
+        protected final MultiComparator cmp;
+
+        public PriorityQueueComparator(MultiComparator cmp) {
+            this.cmp = cmp;
+        }
+
+        @Override
+        public int compare(PriorityQueueElement elementA, PriorityQueueElement elementB) {
+            int result = cmp.compare(elementA.getTuple(), elementB.getTuple());
+            if (result != 0) {
+                return result;
+            }
+            if (elementA.getCursorIndex() > elementB.getCursorIndex()) {
+                return 1;
+            } else {
+                return -1;
+            }
+        }
+
+        public MultiComparator getMultiComparator() {
+            return cmp;
+        }
+    }
+
+    protected void setPriorityQueueComparator() {
+        if (pqCmp == null || cmp != pqCmp.getMultiComparator()) {
+            pqCmp = new PriorityQueueComparator(cmp);
+        }
+    }
+
+    protected int compare(MultiComparator cmp, ITupleReference tupleA, ITupleReference tupleB) {
+        return cmp.compare(tupleA, tupleB);
+    }
+}
\ 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/LSMOperationType.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMOperationType.java
new file mode 100644
index 0000000..981cefe
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMOperationType.java
@@ -0,0 +1,10 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+public enum LSMOperationType {
+    SEARCH,
+    MODIFICATION,
+    FORCE_MODIFICATION,
+    FLUSH,
+    MERGE,
+    NOOP
+}
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
new file mode 100644
index 0000000..7cc29a5
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java
@@ -0,0 +1,146 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessorInternal;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
+
+public abstract class LSMTreeIndexAccessor implements ILSMIndexAccessorInternal {
+    protected ILSMHarness lsmHarness;
+    protected ILSMIndexOperationContext ctx;
+
+    public LSMTreeIndexAccessor(ILSMHarness lsmHarness, ILSMIndexOperationContext ctx) {
+        this.lsmHarness = lsmHarness;
+        this.ctx = ctx;
+    }
+
+    @Override
+    public void insert(ITupleReference tuple) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.INSERT);
+        lsmHarness.modify(ctx, false, tuple);
+    }
+
+    @Override
+    public void update(ITupleReference tuple) throws HyracksDataException, IndexException {
+        // Update is the same as insert.
+        ctx.setOperation(IndexOperation.UPDATE);
+        lsmHarness.modify(ctx, false, tuple);
+    }
+
+    @Override
+    public void delete(ITupleReference tuple) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.DELETE);
+        lsmHarness.modify(ctx, false, tuple);
+    }
+
+    @Override
+    public void upsert(ITupleReference tuple) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.UPSERT);
+        lsmHarness.modify(ctx, false, tuple);
+    }
+
+    @Override
+    public boolean tryInsert(ITupleReference tuple) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.INSERT);
+        return lsmHarness.modify(ctx, true, tuple);
+    }
+
+    @Override
+    public boolean tryDelete(ITupleReference tuple) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.DELETE);
+        return lsmHarness.modify(ctx, true, tuple);
+    }
+
+    @Override
+    public boolean tryUpdate(ITupleReference tuple) throws HyracksDataException, IndexException {
+        // Update is the same as insert.
+        ctx.setOperation(IndexOperation.UPDATE);
+        return lsmHarness.modify(ctx, true, tuple);
+    }
+
+    @Override
+    public boolean tryUpsert(ITupleReference tuple) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.UPSERT);
+        return lsmHarness.modify(ctx, true, tuple);
+    }
+
+    @Override
+    public void search(IIndexCursor cursor, ISearchPredicate searchPred) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.SEARCH);
+        lsmHarness.search(ctx, cursor, searchPred);
+    }
+
+    @Override
+    public void flush(ILSMIOOperation operation) throws HyracksDataException, IndexException {
+        lsmHarness.flush(ctx, operation);
+    }
+
+    @Override
+    public void merge(ILSMIOOperation operation) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.MERGE);
+        lsmHarness.merge(ctx, operation);
+    }
+
+    @Override
+    public void physicalDelete(ITupleReference tuple) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.PHYSICALDELETE);
+        lsmHarness.modify(ctx, false, tuple);
+    }
+
+    @Override
+    public void scheduleFlush(ILSMIOOperationCallback callback) throws HyracksDataException {
+        ctx.setOperation(IndexOperation.FLUSH);
+        lsmHarness.scheduleFlush(ctx, callback);
+    }
+
+    @Override
+    public void scheduleMerge(ILSMIOOperationCallback callback) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.MERGE);
+        lsmHarness.scheduleMerge(ctx, callback);
+    }
+
+    @Override
+    public void noOp() throws HyracksDataException {
+        lsmHarness.noOp(ctx);
+    }
+
+    @Override
+    public void forcePhysicalDelete(ITupleReference tuple) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.PHYSICALDELETE);
+        lsmHarness.forceModify(ctx, tuple);
+    }
+
+    @Override
+    public void forceInsert(ITupleReference tuple) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.INSERT);
+        lsmHarness.forceModify(ctx, tuple);
+    }
+
+    @Override
+    public void forceDelete(ITupleReference tuple) throws HyracksDataException, IndexException {
+        ctx.setOperation(IndexOperation.DELETE);
+        lsmHarness.forceModify(ctx, tuple);
+    }
+}
\ 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/NoMergePolicy.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoMergePolicy.java
new file mode 100644
index 0000000..5d36c09
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoMergePolicy.java
@@ -0,0 +1,14 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
+
+public enum NoMergePolicy implements ILSMMergePolicy {
+    INSTANCE;
+
+    @Override
+    public void diskComponentAdded(ILSMIndex index, int totalNumDiskComponents) {
+        // Do nothing
+    }
+
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpIOOperationCallback.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpIOOperationCallback.java
new file mode 100644
index 0000000..b123b30
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpIOOperationCallback.java
@@ -0,0 +1,34 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+
+public enum NoOpIOOperationCallback implements ILSMIOOperationCallback, ILSMIOOperationCallbackProvider {
+    INSTANCE;
+
+    @Override
+    public void beforeOperation() throws HyracksDataException {
+        // Do nothing.
+    }
+
+    @Override
+    public void afterOperation(List<ILSMComponent> oldComponents, ILSMComponent newComponent)
+            throws HyracksDataException {
+        // Do nothing.
+    }
+
+    @Override
+    public void afterFinalize(ILSMComponent newComponent) throws HyracksDataException {
+        // Do nothing.
+    }
+
+    @Override
+    public ILSMIOOperationCallback getIOOperationCallback(ILSMIndex index) {
+        return INSTANCE;
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpOperationTrackerFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpOperationTrackerFactory.java
new file mode 100644
index 0000000..97ec50e
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpOperationTrackerFactory.java
@@ -0,0 +1,48 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+
+/**
+ * Operation tracker that does nothing.
+ * WARNING: This op tracker should only be used for specific testing purposes.
+ * It is assumed than an op tracker cooperates with an lsm index to synchronize flushes with
+ * regular operations, and this implementation does no such tracking at all.
+ */
+public class NoOpOperationTrackerFactory implements ILSMOperationTrackerFactory {
+    private static final long serialVersionUID = 1L;
+
+    public static NoOpOperationTrackerFactory INSTANCE = new NoOpOperationTrackerFactory();
+
+    @Override
+    public ILSMOperationTracker createOperationTracker(ILSMIndex index) {
+        return new ILSMOperationTracker() {
+
+            @Override
+            public void completeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+                    IModificationOperationCallback modificationCallback) throws HyracksDataException {
+                // Do nothing.
+            }
+
+            @Override
+            public void beforeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+                    IModificationOperationCallback modificationCallback) throws HyracksDataException {
+            }
+
+            @Override
+            public void afterOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+                    IModificationOperationCallback modificationCallback) throws HyracksDataException {
+                // Do nothing.                        
+            }
+        };
+    }
+
+    // Enforce singleton.
+    private NoOpOperationTrackerFactory() {
+    }
+
+};
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SynchronousScheduler.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SynchronousScheduler.java
new file mode 100644
index 0000000..9bbd394
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SynchronousScheduler.java
@@ -0,0 +1,19 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
+
+public enum SynchronousScheduler implements ILSMIOOperationScheduler {
+    INSTANCE;
+
+    @Override
+    public void scheduleOperation(ILSMIOOperation operation) throws HyracksDataException {
+        try {
+            operation.perform();
+        } catch (IndexException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SynchronousSchedulerProvider.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SynchronousSchedulerProvider.java
new file mode 100644
index 0000000..72d9d1d
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SynchronousSchedulerProvider.java
@@ -0,0 +1,15 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
+
+public enum SynchronousSchedulerProvider implements ILSMIOOperationSchedulerProvider {
+    INSTANCE;
+
+    @Override
+    public ILSMIOOperationScheduler getIOScheduler(IHyracksTaskContext ctx) {
+        return SynchronousScheduler.INSTANCE;
+    }
+
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingOperationTrackerFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingOperationTrackerFactory.java
new file mode 100644
index 0000000..3b4b00f
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingOperationTrackerFactory.java
@@ -0,0 +1,21 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+
+public class ThreadCountingOperationTrackerFactory implements ILSMOperationTrackerFactory {
+
+    private static final long serialVersionUID = 1L;
+    
+    public static ThreadCountingOperationTrackerFactory INSTANCE = new ThreadCountingOperationTrackerFactory(); 
+    
+    @Override
+    public ILSMOperationTracker createOperationTracker(ILSMIndex index) {
+        return new ThreadCountingTracker(index);
+    }
+
+    // Enforce singleton.
+    private ThreadCountingOperationTrackerFactory() {
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java
new file mode 100644
index 0000000..7fee06e
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java
@@ -0,0 +1,49 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+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.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.api.ILSMOperationTracker;
+
+public class ThreadCountingTracker implements ILSMOperationTracker {
+    private final AtomicInteger threadRefCount;
+    private final ILSMIndex index;
+
+    public ThreadCountingTracker(ILSMIndex index) {
+        this.index = index;
+        this.threadRefCount = new AtomicInteger();
+    }
+
+    @Override
+    public void beforeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+            IModificationOperationCallback modificationCallback) throws HyracksDataException {
+        if (opType == LSMOperationType.MODIFICATION) {
+            threadRefCount.incrementAndGet();
+        }
+    }
+
+    @Override
+    public void afterOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+            IModificationOperationCallback modificationCallback) throws HyracksDataException {
+        // The operation is considered inactive, immediately after leaving the index.
+        completeOperation(opType, searchCallback, modificationCallback);
+    }
+
+    @Override
+    public void completeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+            IModificationOperationCallback modificationCallback) throws HyracksDataException {
+        // Flush will only be handled by last exiting thread.
+        if (opType == LSMOperationType.MODIFICATION) {
+            if (threadRefCount.decrementAndGet() == 0 && index.getFlushStatus(index)) {
+                ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
+                        NoOpOperationCallback.INSTANCE);
+                accessor.scheduleFlush(NoOpIOOperationCallback.INSTANCE);
+            }
+        }
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/TreeIndexFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/TreeIndexFactory.java
new file mode 100644
index 0000000..f570058
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/TreeIndexFactory.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManagerFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
+
+public abstract class TreeIndexFactory<T extends ITreeIndex> extends IndexFactory<T> {
+
+    protected final ITreeIndexFrameFactory interiorFrameFactory;
+    protected final ITreeIndexFrameFactory leafFrameFactory;
+    protected final IBinaryComparatorFactory[] cmpFactories;
+    protected final int fieldCount;
+
+    public TreeIndexFactory(IBufferCache bufferCache, IFileMapProvider fileMapProvider,
+            IFreePageManagerFactory freePageManagerFactory, ITreeIndexFrameFactory interiorFrameFactory,
+            ITreeIndexFrameFactory leafFrameFactory, IBinaryComparatorFactory[] cmpFactories, int fieldCount) {
+        super(bufferCache, fileMapProvider, freePageManagerFactory);
+        this.interiorFrameFactory = interiorFrameFactory;
+        this.leafFrameFactory = leafFrameFactory;
+        this.cmpFactories = cmpFactories;
+        this.fieldCount = fieldCount;
+    }
+}
\ No newline at end of file