diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/datagen/DataGenThread.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/datagen/DataGenThread.java
index 1a6f4df..ff29b33 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/datagen/DataGenThread.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/datagen/DataGenThread.java
@@ -51,6 +51,19 @@
         ringPos = 0;
     }
     
+    public DataGenThread(int numConsumers, int maxNumBatches, int batchSize, ISerializerDeserializer[] fieldSerdes,
+            IFieldValueGenerator[] fieldGens, int rndSeed, int maxOutstandingBatches) {
+        this.maxNumBatches = maxNumBatches;
+        this.maxOutstandingBatches = maxOutstandingBatches;
+        rnd = new Random(rndSeed);
+        tupleBatches = new TupleBatch[maxOutstandingBatches];
+        for (int i = 0; i < maxOutstandingBatches; i++) {
+            tupleBatches[i] = new TupleBatch(batchSize, fieldGens, fieldSerdes, 0);
+        }
+        tupleBatchQueue = new LinkedBlockingQueue<TupleBatch>(maxOutstandingBatches);
+        ringPos = 0;
+    }
+    
     @Override
     public void run() {
         while(numBatches < maxNumBatches) {
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/datagen/TupleGenerator.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/datagen/TupleGenerator.java
index 1099af2..d0a1062 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/datagen/TupleGenerator.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/datagen/TupleGenerator.java
@@ -69,4 +69,12 @@
             fieldGen.reset();
         }
     }
+    
+    public ISerializerDeserializer[] getFieldSerdes() {
+        return fieldSerdes;
+    }
+    
+    public IFieldValueGenerator[] getFieldGens() {
+        return fieldGens;
+    }
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
index 4965e45..deb1c7d 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
@@ -388,7 +388,6 @@
     }
 
     @Override
-    // TODO: Deal with deletions properly.
     public void search(IIndexCursor cursor, List<Object> diskComponents, ISearchPredicate pred, IIndexOpContext ictx,
             boolean includeMemComponent, AtomicInteger searcherRefCount) throws HyracksDataException, IndexException {
         int numComponents = (includeMemComponent) ? diskComponents.size() : diskComponents.size() + 1;
@@ -694,4 +693,8 @@
     public IBinaryComparatorFactory[] getTokenCmpFactories() {
         return tokenCmpFactories;
     }
+    
+    public IBinaryTokenizerFactory getTokenizerFactory() {
+        return tokenizerFactory;
+    }
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexRangeSearchCursor.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexRangeSearchCursor.java
index 3eee4b7..404fe44 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexRangeSearchCursor.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexRangeSearchCursor.java
@@ -54,7 +54,9 @@
         // For searching the deleted-keys BTrees.
         this.keysOnlyTuple = lsmInitState.getKeysOnlyTuple();
         deletedKeysBTreeAccessors = lsmInitState.getDeletedKeysBTreeAccessors();
-        deletedKeysBTreeCursor = deletedKeysBTreeAccessors.get(0).createSearchCursor();        
+        if (!deletedKeysBTreeAccessors.isEmpty()) {
+            deletedKeysBTreeCursor = deletedKeysBTreeAccessors.get(0).createSearchCursor();
+        }
         MultiComparator keyCmp = lsmInitState.getKeyComparator();
         keySearchPred = new RangePredicate(keysOnlyTuple, keysOnlyTuple, true, true, keyCmp, keyCmp);
         
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexMultiThreadTest.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexMultiThreadTest.java
index d02e6a1..f6a6ee0 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexMultiThreadTest.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexMultiThreadTest.java
@@ -26,13 +26,12 @@
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
-import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.UTF8StringSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
 import edu.uci.ics.hyracks.storage.am.common.IIndexTestWorkerFactory;
+import edu.uci.ics.hyracks.storage.am.common.IndexMultiThreadTestDriver;
 import edu.uci.ics.hyracks.storage.am.common.TestWorkloadConf;
-import edu.uci.ics.hyracks.storage.am.common.TreeIndexMultiThreadTestDriver;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
@@ -63,8 +62,6 @@
 
     protected abstract String getIndexTypeName();
 
-    protected abstract FileReference getFileReference();
-
     protected void runTest(ISerializerDeserializer[] fieldSerdes, int numKeys, int numThreads, TestWorkloadConf conf,
             String dataMsg) throws InterruptedException, TreeIndexException, HyracksException {
         setUp();
@@ -84,9 +81,9 @@
         // 4 batches per thread.
         int batchSize = (NUM_OPERATIONS / numThreads) / 4;
 
-        TreeIndexMultiThreadTestDriver driver = new TreeIndexMultiThreadTestDriver(index, workerFactory, fieldSerdes,
+        IndexMultiThreadTestDriver driver = new IndexMultiThreadTestDriver(index, workerFactory, fieldSerdes,
                 conf.ops, conf.opProbs);
-        driver.init(getFileReference());
+        driver.init();
         long[] times = driver.run(numThreads, 1, NUM_OPERATIONS, batchSize);
         index.validate();
         driver.deinit();
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/common/TreeIndexMultiThreadTestDriver.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/common/IndexMultiThreadTestDriver.java
similarity index 86%
rename from hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/common/TreeIndexMultiThreadTestDriver.java
rename to hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/common/IndexMultiThreadTestDriver.java
index bb7f90d..6bd0f9a 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/common/TreeIndexMultiThreadTestDriver.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/common/IndexMultiThreadTestDriver.java
@@ -17,23 +17,22 @@
 
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector.TestOperation;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
 import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
 
 @SuppressWarnings("rawtypes")
-public class TreeIndexMultiThreadTestDriver {
-    private static final int RANDOM_SEED = 50;
+public class IndexMultiThreadTestDriver {
+    protected static final int RANDOM_SEED = 50;
     // Means no additional payload. Only the specified fields.
-    private static final int PAYLOAD_SIZE = 0;
-    private final TestOperationSelector opSelector;
-    private final ISerializerDeserializer[] fieldSerdes;
-    private final IIndex index;
-    private final IIndexTestWorkerFactory workerFactory;
+    protected static final int PAYLOAD_SIZE = 0;
+    protected final TestOperationSelector opSelector;
+    protected final ISerializerDeserializer[] fieldSerdes;
+    protected final IIndex index;
+    protected final IIndexTestWorkerFactory workerFactory;
 
-    public TreeIndexMultiThreadTestDriver(IIndex index, IIndexTestWorkerFactory workerFactory,
+    public IndexMultiThreadTestDriver(IIndex index, IIndexTestWorkerFactory workerFactory,
             ISerializerDeserializer[] fieldSerdes, TestOperation[] ops, double[] opProbs) {
         this.index = index;
         this.workerFactory = workerFactory;
@@ -41,7 +40,7 @@
         this.opSelector = new TestOperationSelector(ops, opProbs);
     }
 
-    public void init(FileReference file) throws HyracksDataException {
+    public void init() throws HyracksDataException {
         index.create();
         index.activate();
     }
@@ -81,6 +80,7 @@
 
     public void deinit() throws HyracksDataException {
         index.deactivate();
+        index.destroy();
     }
 
     // To allow subclasses to override the data gen params.
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeMultiThreadTest.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeMultiThreadTest.java
index 6ec097b..bb0e91d 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeMultiThreadTest.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeMultiThreadTest.java
@@ -26,15 +26,14 @@
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
-import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.data.std.primitive.DoublePointable;
 import edu.uci.ics.hyracks.data.std.primitive.IntegerPointable;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.DoubleSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
 import edu.uci.ics.hyracks.storage.am.common.IIndexTestWorkerFactory;
+import edu.uci.ics.hyracks.storage.am.common.IndexMultiThreadTestDriver;
 import edu.uci.ics.hyracks.storage.am.common.TestWorkloadConf;
-import edu.uci.ics.hyracks.storage.am.common.TreeIndexMultiThreadTestDriver;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
@@ -76,8 +75,6 @@
 
     protected abstract String getIndexTypeName();
 
-    protected abstract FileReference getFileReference();
-
     protected void runTest(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType,
             int numThreads, TestWorkloadConf conf, String dataMsg) throws HyracksException, InterruptedException,
@@ -102,9 +99,9 @@
         // 4 batches per thread.
         int batchSize = (NUM_OPERATIONS / numThreads) / 4;
 
-        TreeIndexMultiThreadTestDriver driver = new TreeIndexMultiThreadTestDriver(index, workerFactory, fieldSerdes,
+        IndexMultiThreadTestDriver driver = new IndexMultiThreadTestDriver(index, workerFactory, fieldSerdes,
                 conf.ops, conf.opProbs);
-        driver.init(getFileReference());
+        driver.init();
         long[] times = driver.run(numThreads, 1, NUM_OPERATIONS, batchSize);
         driver.deinit();
 
diff --git a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeMultiThreadTest.java
index 5c8f1c7..746e885 100644
--- a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeMultiThreadTest.java
+++ b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeMultiThreadTest.java
@@ -20,7 +20,6 @@
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.storage.am.btree.OrderedIndexMultiThreadTest;
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.btree.util.BTreeTestHarness;
@@ -90,11 +89,6 @@
     }
 
     @Override
-    protected FileReference getFileReference() {
-        return harness.getFileReference();
-    }
-
-    @Override
     protected String getIndexTypeName() {
         return "BTree";
     }
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
index 649da09..e4cb37a 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
@@ -21,7 +21,6 @@
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
-import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.storage.am.btree.OrderedIndexMultiThreadTest;
 import edu.uci.ics.hyracks.storage.am.common.IIndexTestWorkerFactory;
 import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector.TestOperation;
@@ -112,9 +111,4 @@
     protected String getIndexTypeName() {
         return "LSMBTree";
     }
-
-    @Override
-    protected FileReference getFileReference() {
-        return harness.getFileReference();
-    }
 }
diff --git a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexMultiThreadTest.java
new file mode 100644
index 0000000..7471492
--- /dev/null
+++ b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexMultiThreadTest.java
@@ -0,0 +1,142 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.invertedindex.multithread;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import org.junit.Test;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector.TestOperation;
+import edu.uci.ics.hyracks.storage.am.common.TestWorkloadConf;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+import edu.uci.ics.hyracks.storage.am.common.datagen.ProbabilityHelper;
+import edu.uci.ics.hyracks.storage.am.common.datagen.TupleGenerator;
+import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.common.LSMInvertedIndexTestHarness;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.util.LSMInvertedIndexTestContext;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.util.LSMInvertedIndexTestContext.InvertedIndexType;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.util.LSMInvertedIndexTestUtils;
+
+public class LSMInvertedIndexMultiThreadTest {
+
+    protected final Logger LOGGER = Logger.getLogger(LSMInvertedIndexMultiThreadTest.class.getName());
+    
+    // Machine-specific number of threads to use for testing.
+    protected final int REGULAR_NUM_THREADS = Runtime.getRuntime().availableProcessors();
+    // Excessive number of threads for testing.
+    protected final int EXCESSIVE_NUM_THREADS = Runtime.getRuntime().availableProcessors() * 4;
+    protected final int NUM_OPERATIONS = AccessMethodTestsConfig.BTREE_MULTITHREAD_NUM_OPERATIONS;
+    
+    private final LSMInvertedIndexTestHarness harness = new LSMInvertedIndexTestHarness();
+    private final LSMInvertedIndexWorkerFactory workerFactory = new LSMInvertedIndexWorkerFactory();
+    private final ArrayList<TestWorkloadConf> workloadConfs = getTestWorkloadConf();
+    
+    protected void setUp() throws HyracksException {
+        harness.setUp();
+    }
+
+    protected void tearDown() throws HyracksDataException {
+        harness.tearDown();
+    }
+
+    protected void runTest(LSMInvertedIndexTestContext testCtx, TupleGenerator tupleGen, int numThreads, TestWorkloadConf conf,
+            String dataMsg) throws InterruptedException, TreeIndexException, HyracksException {
+        if (LOGGER.isLoggable(Level.INFO)) {
+            LOGGER.info("LSMInvertedIndex MultiThread Test:\nData: " + dataMsg + "; Threads: " + numThreads
+                    + "; Workload: " + conf.toString() + ".");
+        }
+
+        // 4 batches per thread.
+        int batchSize = (NUM_OPERATIONS / numThreads) / 4;
+
+        LSMInvertedIndexMultiThreadTestDriver driver = new LSMInvertedIndexMultiThreadTestDriver(testCtx.getIndex(),
+                workerFactory, tupleGen.getFieldSerdes(), tupleGen.getFieldGens(), conf.ops, conf.opProbs);
+        driver.init();
+        long[] times = driver.run(numThreads, 1, NUM_OPERATIONS, batchSize);
+        testCtx.getIndex().validate();
+        driver.deinit();
+
+        if (LOGGER.isLoggable(Level.INFO)) {
+            LOGGER.info("LSMInvertedIndex MultiThread Test Time: " + times[0] + "ms");
+        }
+    }
+
+    protected ArrayList<TestWorkloadConf> getTestWorkloadConf() {
+        ArrayList<TestWorkloadConf> workloadConfs = new ArrayList<TestWorkloadConf>();
+
+        // Insert only workload.
+        TestOperation[] insertOnlyOps = new TestOperation[] { TestOperation.INSERT };
+        workloadConfs.add(new TestWorkloadConf(insertOnlyOps, ProbabilityHelper
+                .getUniformProbDist(insertOnlyOps.length)));
+
+        // Insert and merge workload.
+        TestOperation[] insertMergeOps = new TestOperation[] { TestOperation.INSERT, TestOperation.MERGE };
+        workloadConfs.add(new TestWorkloadConf(insertMergeOps, ProbabilityHelper
+                .getUniformProbDist(insertMergeOps.length)));
+
+        // Inserts mixed with point searches and scans.
+        TestOperation[] insertSearchOnlyOps = new TestOperation[] { TestOperation.INSERT, TestOperation.POINT_SEARCH,
+                TestOperation.SCAN };
+        workloadConfs.add(new TestWorkloadConf(insertSearchOnlyOps, ProbabilityHelper
+                .getUniformProbDist(insertSearchOnlyOps.length)));
+
+        // Inserts, and deletes.
+        TestOperation[] insertDeleteUpdateOps = new TestOperation[] { TestOperation.INSERT, TestOperation.DELETE };
+        workloadConfs.add(new TestWorkloadConf(insertDeleteUpdateOps, ProbabilityHelper
+                .getUniformProbDist(insertDeleteUpdateOps.length)));
+
+        // Inserts, deletes and merges.
+        TestOperation[] insertDeleteUpdateMergeOps = new TestOperation[] { TestOperation.INSERT, TestOperation.DELETE,
+                TestOperation.MERGE };
+        workloadConfs.add(new TestWorkloadConf(insertDeleteUpdateMergeOps, ProbabilityHelper
+                .getUniformProbDist(insertDeleteUpdateMergeOps.length)));
+
+        // All operations except merge.
+        TestOperation[] allNoMergeOps = new TestOperation[] { TestOperation.INSERT, TestOperation.DELETE,
+                TestOperation.POINT_SEARCH, TestOperation.SCAN };
+        workloadConfs.add(new TestWorkloadConf(allNoMergeOps, ProbabilityHelper
+                .getUniformProbDist(allNoMergeOps.length)));
+
+        // All operations.
+        TestOperation[] allOps = new TestOperation[] { TestOperation.INSERT, TestOperation.DELETE,
+                TestOperation.POINT_SEARCH, TestOperation.SCAN, TestOperation.MERGE };
+        workloadConfs.add(new TestWorkloadConf(allOps, ProbabilityHelper.getUniformProbDist(allOps.length)));
+
+        return workloadConfs;
+    }
+    
+    @Test
+    public void wordTokensInvIndexTest() throws IOException, IndexException, InterruptedException {
+        String dataMsg = "Documents";
+        int[] numThreads = new int[] { EXCESSIVE_NUM_THREADS };
+        for (int i = 0; i < numThreads.length; i++) {
+            for (TestWorkloadConf conf : workloadConfs) {
+                setUp();
+                LSMInvertedIndexTestContext testCtx = LSMInvertedIndexTestUtils.createWordInvIndexTestContext(harness,
+                        InvertedIndexType.LSM);
+                TupleGenerator tupleGen = LSMInvertedIndexTestUtils.createStringDocumentTupleGen(harness.getRandom());
+                runTest(testCtx, tupleGen, numThreads[i], conf, dataMsg);
+                tearDown();
+            }
+        }
+    }
+}
diff --git a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexMultiThreadTestDriver.java b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexMultiThreadTestDriver.java
new file mode 100644
index 0000000..dd7a7a8
--- /dev/null
+++ b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexMultiThreadTestDriver.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.invertedindex.multithread;
+
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.storage.am.common.IIndexTestWorkerFactory;
+import edu.uci.ics.hyracks.storage.am.common.IndexMultiThreadTestDriver;
+import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector.TestOperation;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
+import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
+import edu.uci.ics.hyracks.storage.am.common.datagen.IFieldValueGenerator;
+
+@SuppressWarnings("rawtypes")
+public class LSMInvertedIndexMultiThreadTestDriver extends IndexMultiThreadTestDriver {
+
+    protected final IFieldValueGenerator[] fieldGens;
+
+    public LSMInvertedIndexMultiThreadTestDriver(IIndex index, IIndexTestWorkerFactory workerFactory,
+            ISerializerDeserializer[] fieldSerdes, IFieldValueGenerator[] fieldGens, TestOperation[] ops,
+            double[] opProbs) {
+        super(index, workerFactory, fieldSerdes, ops, opProbs);
+        this.fieldGens = fieldGens;
+    }
+
+    public DataGenThread createDatagenThread(int numThreads, int numBatches, int batchSize) {
+        return new DataGenThread(numThreads, numBatches, batchSize, fieldSerdes, fieldGens, RANDOM_SEED, 2 * numThreads);
+    }
+}
diff --git a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexTestWorker.java b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexTestWorker.java
new file mode 100644
index 0000000..0176d98
--- /dev/null
+++ b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexTestWorker.java
@@ -0,0 +1,139 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.invertedindex.multithread;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.dataflow.common.util.TupleUtils;
+import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
+import edu.uci.ics.hyracks.storage.am.common.AbstractIndexTestWorker;
+import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector;
+import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector.TestOperation;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
+import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMMergeInProgressException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoOpIOOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexSearchModifier;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.exceptions.OccurrenceThresholdPanicException;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.impls.LSMInvertedIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.impls.LSMInvertedIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.search.ConjunctiveSearchModifier;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.search.InvertedIndexSearchPredicate;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.search.JaccardSearchModifier;
+import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizerFactory;
+
+public class LSMInvertedIndexTestWorker extends AbstractIndexTestWorker {
+
+    protected final LSMInvertedIndex invIndex;
+    protected final List<ITupleReference> documentCorpus = new ArrayList<ITupleReference>();    
+    protected final Random rnd = new Random(50);
+    
+    protected final IInvertedIndexSearchModifier[] TEST_SEARCH_MODIFIERS = new IInvertedIndexSearchModifier[] {
+            new ConjunctiveSearchModifier(), new JaccardSearchModifier(0.8f), new JaccardSearchModifier(0.5f) };
+    
+    public LSMInvertedIndexTestWorker(DataGenThread dataGen, TestOperationSelector opSelector, IIndex index,
+            int numBatches) {
+        super(dataGen, opSelector, index, numBatches);
+        invIndex = (LSMInvertedIndex) index;
+    }
+
+    @Override
+    public void performOp(ITupleReference tuple, TestOperation op) throws HyracksDataException, IndexException {
+        LSMInvertedIndexAccessor accessor = (LSMInvertedIndexAccessor) indexAccessor;
+        IIndexCursor searchCursor = accessor.createSearchCursor();
+        IIndexCursor rangeSearchCursor = accessor.createRangeSearchCursor();
+        RangePredicate rangePred = new RangePredicate(null, null, true, true, null, null);
+        IBinaryTokenizerFactory tokenizerFactory = invIndex.getTokenizerFactory();
+        int searchModifierIndex = Math.abs(rnd.nextInt()) % TEST_SEARCH_MODIFIERS.length;
+        InvertedIndexSearchPredicate searchPred = new InvertedIndexSearchPredicate(tokenizerFactory.createTokenizer(),
+                TEST_SEARCH_MODIFIERS[searchModifierIndex]);
+        
+        switch (op) {
+            case INSERT: {
+                accessor.insert(tuple);
+                // Add tuple to document corpus so we can delete it.
+                ITupleReference copyTuple = TupleUtils.copyTuple(tuple);
+                documentCorpus.add(copyTuple);
+                break;
+            }
+
+            case DELETE: {
+                // Randomly pick a document from the corpus to delete.
+                if (!documentCorpus.isEmpty()) {
+                    int docIndex = Math.abs(rnd.nextInt()) % documentCorpus.size();
+                    ITupleReference deleteTuple = documentCorpus.get(docIndex);
+                    accessor.delete(deleteTuple);
+                    // Swap tupleIndex with last element.
+                    documentCorpus.set(docIndex, documentCorpus.get(documentCorpus.size() - 1));
+                    documentCorpus.remove(documentCorpus.size() - 1);
+                } else {
+                    // Treat this case as an insert.
+                    accessor.insert(tuple);
+                    // Add tuple to document corpus so we can delete it.
+                    ITupleReference copyTuple = TupleUtils.copyTuple(tuple);
+                    documentCorpus.add(copyTuple);
+                }
+                break;
+            }
+
+            case POINT_SEARCH: {
+                searchCursor.reset();
+                searchPred.setQueryTuple(tuple);
+                searchPred.setQueryFieldIndex(0);
+                try {
+                    accessor.search(searchCursor, searchPred);
+                    consumeCursorTuples(searchCursor);
+                } catch (OccurrenceThresholdPanicException e) {
+                    // Ignore.
+                }                
+                break;
+            }
+
+            case SCAN: {
+                rangeSearchCursor.reset();
+                accessor.rangeSearch(rangeSearchCursor, rangePred);
+                consumeCursorTuples(rangeSearchCursor);
+                break;
+            }
+
+            case MERGE: {
+                try {
+                    ILSMIOOperation ioop = accessor.createMergeOperation(NoOpIOOperationCallback.INSTANCE);
+                    if (ioop != null) {
+                        accessor.merge(ioop);
+                    }
+                } catch (LSMMergeInProgressException e) {
+                    // Ignore ongoing merges. Do an insert instead.
+                    accessor.insert(tuple);
+                    // Add tuple to document corpus so we can delete it.
+                    ITupleReference copyTuple = TupleUtils.copyTuple(tuple);
+                    documentCorpus.add(copyTuple);
+                }
+                break;
+            }
+
+            default:
+                throw new HyracksDataException("Op " + op.toString() + " not supported.");
+        }
+    }
+}
diff --git a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexWorkerFactory.java b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexWorkerFactory.java
new file mode 100644
index 0000000..877daed
--- /dev/null
+++ b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/multithread/LSMInvertedIndexWorkerFactory.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.invertedindex.multithread;
+
+import edu.uci.ics.hyracks.storage.am.common.AbstractIndexTestWorker;
+import edu.uci.ics.hyracks.storage.am.common.IIndexTestWorkerFactory;
+import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
+import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
+
+public class LSMInvertedIndexWorkerFactory implements IIndexTestWorkerFactory {
+    @Override
+    public AbstractIndexTestWorker create(DataGenThread dataGen, TestOperationSelector opSelector,
+            IIndex index, int numBatches) {
+        return new LSMInvertedIndexTestWorker(dataGen, opSelector, index, numBatches);
+    }
+}
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
index a3e452c..8b7ce02 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
@@ -21,7 +21,6 @@
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
-import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.storage.am.common.IIndexTestWorkerFactory;
 import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector.TestOperation;
 import edu.uci.ics.hyracks.storage.am.common.TestWorkloadConf;
@@ -119,9 +118,4 @@
         return "LSMRTree";
     }
 
-    @Override
-    protected FileReference getFileReference() {
-        return harness.getFileReference();
-    }
-
 }
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
index 6b76150..a5b864c 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
@@ -21,7 +21,6 @@
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
-import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.storage.am.common.IIndexTestWorkerFactory;
 import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector.TestOperation;
 import edu.uci.ics.hyracks.storage.am.common.TestWorkloadConf;
@@ -120,9 +119,4 @@
         return "LSMRTree";
     }
 
-    @Override
-    protected FileReference getFileReference() {
-        return harness.getFileReference();
-    }
-
 }
diff --git a/hyracks-tests/hyracks-storage-am-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/rtree/multithread/RTreeMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/rtree/multithread/RTreeMultiThreadTest.java
index 27faeb3..ee245e8 100644
--- a/hyracks-tests/hyracks-storage-am-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/rtree/multithread/RTreeMultiThreadTest.java
+++ b/hyracks-tests/hyracks-storage-am-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/rtree/multithread/RTreeMultiThreadTest.java
@@ -20,7 +20,6 @@
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.storage.am.common.IIndexTestWorkerFactory;
 import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector.TestOperation;
 import edu.uci.ics.hyracks.storage.am.common.TestWorkloadConf;
@@ -99,9 +98,4 @@
     protected String getIndexTypeName() {
         return "RTree";
     }
-
-    @Override
-    protected FileReference getFileReference() {
-        return harness.getFileReference();
-    }
 }