diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/btree/BTreeOperatorsTest.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/btree/BTreeOperatorsTest.java
index 38c2899..0869b10 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/btree/BTreeOperatorsTest.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/btree/BTreeOperatorsTest.java
@@ -59,10 +59,11 @@
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.BTreeRegistryProvider;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.BTreeSearchOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.BufferCacheProvider;
-import edu.uci.ics.hyracks.storage.am.btree.dataflow.FileMappingProvider;
+import edu.uci.ics.hyracks.storage.am.btree.dataflow.FileMappingProviderProvider;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.FrameTupleReferenceFactory;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.IBTreeRegistryProvider;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.IBufferCacheProvider;
+import edu.uci.ics.hyracks.storage.am.btree.dataflow.IFileMappingProviderProvider;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.ITupleReferenceFactory;
 import edu.uci.ics.hyracks.storage.am.btree.frames.MetaDataFrame;
 import edu.uci.ics.hyracks.storage.am.btree.frames.NSMInteriorFrameFactory;
@@ -75,7 +76,6 @@
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.FileInfo;
 import edu.uci.ics.hyracks.storage.common.file.FileManager;
-import edu.uci.ics.hyracks.storage.common.file.IFileMappingProvider;
 import edu.uci.ics.hyracks.tests.integration.AbstractIntegrationTest;
 
 public class BTreeOperatorsTest extends AbstractIntegrationTest {
@@ -118,7 +118,7 @@
 		
 		IBufferCacheProvider bufferCacheProvider = new BufferCacheProvider();		
 		IBTreeRegistryProvider btreeRegistryProvider = new BTreeRegistryProvider();
-		IFileMappingProvider fileMappingProvider = new FileMappingProvider();
+		IFileMappingProviderProvider fileMappingProviderProvider = new FileMappingProviderProvider();
 				
 		int fieldCount = 3;
 		int keyFieldCount = 1;
@@ -127,7 +127,7 @@
 				
 		int[] fieldPermutation = { 0, 4, 5 };
         
-		BTreeBulkLoadOperatorDescriptor btreeBulkLoad = new BTreeBulkLoadOperatorDescriptor(spec, ordersSplitProvider, ordersDesc, bufferCacheProvider, btreeRegistryProvider, "btreetest.bin", fileMappingProvider, interiorFrameFactory, leafFrameFactory, fieldCount, comparatorFactories, fieldPermutation, 0.7f);		
+		BTreeBulkLoadOperatorDescriptor btreeBulkLoad = new BTreeBulkLoadOperatorDescriptor(spec, ordersSplitProvider, ordersDesc, bufferCacheProvider, btreeRegistryProvider, "btreetest.bin", fileMappingProviderProvider, interiorFrameFactory, leafFrameFactory, fieldCount, comparatorFactories, fieldPermutation, 0.7f);		
 		PartitionConstraint btreePartitionConstraintA = new ExplicitPartitionConstraint(new LocationConstraint[] { new AbsoluteLocationConstraint(NC1_ID) });
 		btreeBulkLoad.setPartitionConstraint(btreePartitionConstraintA);
 				
@@ -225,18 +225,17 @@
     	    	    	
 		IBufferCacheProvider bufferCacheProvider = new BufferCacheProvider();
 		IBTreeRegistryProvider btreeRegistryProvider = new BTreeRegistryProvider();		
-		IFileMappingProvider fileMappingProvider = new FileMappingProvider();
+		IFileMappingProviderProvider fileMappingProviderProvider = new FileMappingProviderProvider();
 		
 		RecordDescriptor recDesc = new RecordDescriptor(
                 new ISerializerDeserializer[] { UTF8StringSerializerDeserializer.INSTANCE, UTF8StringSerializerDeserializer.INSTANCE, UTF8StringSerializerDeserializer.INSTANCE });
 		
 		// TODO: hacky, manually adding file
-		String ncDataPath = System.getProperty("NodeControllerDataPath");
-        String fileName = ncDataPath + "btreetest.bin";		
-		int blubb = fileMappingProvider.mapNameToFileId(fileName, true);
-		System.out.println("BLUBB: " + blubb + " " + fileName);
+		//String ncDataPath = System.getProperty("NodeControllerDataPath");
+        //String fileName = ncDataPath + "btreetest.bin";		
+		//int blubb = fileMappingProviderProvider.getFileMappingProvider().mapNameToFileId(fileName, true);
 		
-		BTreeSearchOperatorDescriptor btreeSearchOp = new BTreeSearchOperatorDescriptor(spec, splitProvider, recDesc, bufferCacheProvider, btreeRegistryProvider, "btreetest.bin", fileMappingProvider, interiorFrameFactory, leafFrameFactory, fieldCount, comparatorFactories, true, searchKeys, comparatorFactories.length);
+		BTreeSearchOperatorDescriptor btreeSearchOp = new BTreeSearchOperatorDescriptor(spec, splitProvider, recDesc, bufferCacheProvider, btreeRegistryProvider, "btreetest.bin", fileMappingProviderProvider, interiorFrameFactory, leafFrameFactory, fieldCount, comparatorFactories, true, searchKeys, comparatorFactories.length);
 		//BTreeDiskOrderScanOperatorDescriptor btreeSearchOp = new BTreeDiskOrderScanOperatorDescriptor(spec, splitProvider, recDesc, bufferCacheProvider, btreeRegistryProvider, 0, "btreetest.bin", interiorFrameFactory, leafFrameFactory, cmp);
 		
 		PartitionConstraint btreePartitionConstraint = new ExplicitPartitionConstraint(new LocationConstraint[] { new AbsoluteLocationConstraint(NC1_ID) });
@@ -325,10 +324,10 @@
         IBufferCache bufferCache = bufferCacheProvider.getBufferCache();
         BTreeRegistry btreeRegistry = btreeRegistryProvider.getBTreeRegistry();        
         FileManager fileManager = bufferCacheProvider.getFileManager();
-        IFileMappingProvider fileMappingProvider = new FileMappingProvider();
+        IFileMappingProviderProvider fileMappingProviderProvider = new FileMappingProviderProvider();
         
         // primary index
-        int fileIdA = fileMappingProvider.mapNameToFileId("/tmp/btreetestA.ix", true);
+        int fileIdA = fileMappingProviderProvider.getFileMappingProvider().mapNameToFileId("/tmp/btreetestA.ix", true);
         File fA = new File("/tmp/btreetestA.ix");
         RandomAccessFile rafA = new RandomAccessFile(fA, "rw");                
         FileInfo fiA = new FileInfo(fileIdA, rafA);
@@ -339,7 +338,7 @@
         btreeRegistry.register(fileIdA, btreeA);
         
         // first secondary index
-        int fileIdB = fileMappingProvider.mapNameToFileId("/tmp/btreetestB.ix", true);
+        int fileIdB = fileMappingProviderProvider.getFileMappingProvider().mapNameToFileId("/tmp/btreetestB.ix", true);
         File fB = new File("/tmp/btreetestB.ix");
         RandomAccessFile rafB = new RandomAccessFile(fB, "rw");   
         FileInfo fiB = new FileInfo(fileIdB, rafB);
@@ -350,7 +349,7 @@
         btreeRegistry.register(fileIdB, btreeB);
         
         // second secondary index
-        int fileIdC = fileMappingProvider.mapNameToFileId("/tmp/btreetestC.ix", true);
+        int fileIdC = fileMappingProviderProvider.getFileMappingProvider().mapNameToFileId("/tmp/btreetestC.ix", true);
         File fC = new File("/tmp/btreetestC.ix");
         RandomAccessFile rafC = new RandomAccessFile(fC, "rw");                
         FileInfo fiC = new FileInfo(fileIdC, rafC);
@@ -364,19 +363,19 @@
         
         // primary index
         int[] fieldPermutationA = { 0,1,2,3,4,5 };                       
-        BTreeInsertUpdateDeleteOperatorDescriptor insertOpA = new BTreeInsertUpdateDeleteOperatorDescriptor(spec, ordersSplitProvider, ordersDesc, bufferCacheProvider, btreeRegistryProvider, "btreetestA.ix", fileMappingProvider, interiorFrameFactory, leafFrameFactory, primaryFieldCount, primaryComparatorFactories, fieldPermutationA, BTreeOp.BTO_INSERT);
+        BTreeInsertUpdateDeleteOperatorDescriptor insertOpA = new BTreeInsertUpdateDeleteOperatorDescriptor(spec, ordersSplitProvider, ordersDesc, bufferCacheProvider, btreeRegistryProvider, "btreetestA.ix", fileMappingProviderProvider, interiorFrameFactory, leafFrameFactory, primaryFieldCount, primaryComparatorFactories, fieldPermutationA, BTreeOp.BTO_INSERT);
         PartitionConstraint insertPartitionConstraintA = new ExplicitPartitionConstraint(new LocationConstraint[] { new AbsoluteLocationConstraint(NC1_ID) });
         insertOpA.setPartitionConstraint(insertPartitionConstraintA);
         
         // first secondary index
         int[] fieldPermutationB = { 3, 0 };                    
-        BTreeInsertUpdateDeleteOperatorDescriptor insertOpB = new BTreeInsertUpdateDeleteOperatorDescriptor(spec, ordersSplitProvider, ordersDesc, bufferCacheProvider, btreeRegistryProvider, "btreetestB.ix", fileMappingProvider, interiorFrameFactory, leafFrameFactory, secondaryFieldCount, secondaryComparatorFactories, fieldPermutationB, BTreeOp.BTO_INSERT);
+        BTreeInsertUpdateDeleteOperatorDescriptor insertOpB = new BTreeInsertUpdateDeleteOperatorDescriptor(spec, ordersSplitProvider, ordersDesc, bufferCacheProvider, btreeRegistryProvider, "btreetestB.ix", fileMappingProviderProvider, interiorFrameFactory, leafFrameFactory, secondaryFieldCount, secondaryComparatorFactories, fieldPermutationB, BTreeOp.BTO_INSERT);
         PartitionConstraint insertPartitionConstraintB = new ExplicitPartitionConstraint(new LocationConstraint[] { new AbsoluteLocationConstraint(NC1_ID) });
         insertOpB.setPartitionConstraint(insertPartitionConstraintB);
 		
         // second secondary index
         int[] fieldPermutationC = { 4, 0 };                       
-        BTreeInsertUpdateDeleteOperatorDescriptor insertOpC = new BTreeInsertUpdateDeleteOperatorDescriptor(spec, ordersSplitProvider, ordersDesc, bufferCacheProvider, btreeRegistryProvider, "btreetestC.ix", fileMappingProvider, interiorFrameFactory, leafFrameFactory, secondaryFieldCount, secondaryComparatorFactories, fieldPermutationC, BTreeOp.BTO_INSERT);
+        BTreeInsertUpdateDeleteOperatorDescriptor insertOpC = new BTreeInsertUpdateDeleteOperatorDescriptor(spec, ordersSplitProvider, ordersDesc, bufferCacheProvider, btreeRegistryProvider, "btreetestC.ix", fileMappingProviderProvider, interiorFrameFactory, leafFrameFactory, secondaryFieldCount, secondaryComparatorFactories, fieldPermutationC, BTreeOp.BTO_INSERT);
         PartitionConstraint insertPartitionConstraintC = new ExplicitPartitionConstraint(new LocationConstraint[] { new AbsoluteLocationConstraint(NC1_ID) });
         insertOpC.setPartitionConstraint(insertPartitionConstraintC);
                 
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/AbstractBTreeOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/AbstractBTreeOperatorDescriptor.java
index 8200c82..ccc229c 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/AbstractBTreeOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/AbstractBTreeOperatorDescriptor.java
@@ -29,7 +29,7 @@
 	private static final long serialVersionUID = 1L;
 	
 	protected String btreeFileName;
-	protected IFileMappingProvider fileMappingProvider;
+	protected IFileMappingProviderProvider fileMappingProviderProvider;
 	
 	protected int fieldCount;
 	protected IBinaryComparatorFactory[] comparatorFactories;	
@@ -40,10 +40,10 @@
 	protected IBufferCacheProvider bufferCacheProvider;
 	protected IBTreeRegistryProvider btreeRegistryProvider;
 		
-	public AbstractBTreeOperatorDescriptor(JobSpecification spec, int inputArity, int outputArity, IFileSplitProvider fileSplitProvider, RecordDescriptor recDesc, IBufferCacheProvider bufferCacheProvider, IBTreeRegistryProvider btreeRegistryProvider,  String btreeFileName, IFileMappingProvider fileMappingProvider, IBTreeInteriorFrameFactory interiorFactory, IBTreeLeafFrameFactory leafFactory, int fieldCount, IBinaryComparatorFactory[] comparatorFactories) {
+	public AbstractBTreeOperatorDescriptor(JobSpecification spec, int inputArity, int outputArity, IFileSplitProvider fileSplitProvider, RecordDescriptor recDesc, IBufferCacheProvider bufferCacheProvider, IBTreeRegistryProvider btreeRegistryProvider,  String btreeFileName, IFileMappingProviderProvider fileMappingProviderProvider, IBTreeInteriorFrameFactory interiorFactory, IBTreeLeafFrameFactory leafFactory, int fieldCount, IBinaryComparatorFactory[] comparatorFactories) {
         super(spec, inputArity, outputArity);
         this.btreeFileName = btreeFileName;
-        this.fileMappingProvider = fileMappingProvider;
+        this.fileMappingProviderProvider = fileMappingProviderProvider;
         this.bufferCacheProvider = bufferCacheProvider;
         this.btreeRegistryProvider = btreeRegistryProvider;        
         this.interiorFrameFactory = interiorFactory;
@@ -57,8 +57,8 @@
 		return btreeFileName;
 	}
 
-	public IFileMappingProvider getFileMappingProvider() {
-		return fileMappingProvider;
+	public IFileMappingProviderProvider getFileMappingProviderProvider() {
+		return fileMappingProviderProvider;
 	}
 
 	public IBinaryComparatorFactory[] getComparatorFactories() {
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorDescriptor.java
index 13ded9a..c101a48 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorDescriptor.java
@@ -25,7 +25,6 @@
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
 import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeInteriorFrameFactory;
 import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrameFactory;
-import edu.uci.ics.hyracks.storage.common.file.IFileMappingProvider;
 
 public class BTreeBulkLoadOperatorDescriptor extends AbstractBTreeOperatorDescriptor {
 	
@@ -38,12 +37,12 @@
 			IFileSplitProvider fileSplitProvider, RecordDescriptor recDesc,
 			IBufferCacheProvider bufferCacheProvider,
 			IBTreeRegistryProvider btreeRegistryProvider,
-			String btreeFileName, IFileMappingProvider fileMappingProvider, IBTreeInteriorFrameFactory interiorFactory,
+			String btreeFileName, IFileMappingProviderProvider fileMappingProviderProvider, IBTreeInteriorFrameFactory interiorFactory,
 			IBTreeLeafFrameFactory leafFactory, int fieldCount, 
 			IBinaryComparatorFactory[] comparatorFactories,			
 			int[] fieldPermutation, float fillFactor) {
 		super(spec, 1, 0, fileSplitProvider, recDesc, bufferCacheProvider,
-				btreeRegistryProvider, btreeFileName, fileMappingProvider, interiorFactory,
+				btreeRegistryProvider, btreeFileName, fileMappingProviderProvider, interiorFactory,
 				leafFactory, fieldCount, comparatorFactories);
 		this.fieldPermutation = fieldPermutation;
 		this.fillFactor = fillFactor;
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorDescriptor.java
index 9d1247f..fa6dba3 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorDescriptor.java
@@ -35,11 +35,11 @@
 			IFileSplitProvider fileSplitProvider, RecordDescriptor recDesc,
 			IBufferCacheProvider bufferCacheProvider,
 			IBTreeRegistryProvider btreeRegistryProvider,
-			String btreeFileName, IFileMappingProvider fileMappingProvider, IBTreeInteriorFrameFactory interiorFactory,
+			String btreeFileName, IFileMappingProviderProvider fileMappingProviderProvider, IBTreeInteriorFrameFactory interiorFactory,
 			IBTreeLeafFrameFactory leafFactory, 
 			int fieldCount, IBinaryComparatorFactory[] comparatorFactories) {
 		super(spec, 0, 1, fileSplitProvider, recDesc, bufferCacheProvider,
-				btreeRegistryProvider, btreeFileName, fileMappingProvider, interiorFactory,
+				btreeRegistryProvider, btreeFileName, fileMappingProviderProvider, interiorFactory,
 				leafFactory, fieldCount, comparatorFactories);
 	}
 	
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorDescriptor.java
index d597530..fa3a72f 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorDescriptor.java
@@ -30,15 +30,15 @@
 	private String btreeFileName;
 	private IBufferCacheProvider bufferCacheProvider;
 	private IBTreeRegistryProvider btreeRegistryProvider;	
-	private IFileMappingProvider fileMappingProvider;
+	private IFileMappingProviderProvider fileMappingProviderProvider;
 	
 	public BTreeDropOperatorDescriptor(JobSpecification spec,			
 			IBufferCacheProvider bufferCacheProvider,
 			IBTreeRegistryProvider btreeRegistryProvider,
-			String btreeFileName, IFileMappingProvider fileMappingProvider) {
+			String btreeFileName, IFileMappingProviderProvider fileMappingProviderProvider) {
 		super(spec, 0, 0);
 		this.btreeFileName = btreeFileName;
-		this.fileMappingProvider = fileMappingProvider;
+		this.fileMappingProviderProvider = fileMappingProviderProvider;
 		this.bufferCacheProvider = bufferCacheProvider;
 		this.btreeRegistryProvider = btreeRegistryProvider;
 	}
@@ -48,6 +48,6 @@
 			IOperatorEnvironment env,
 			IRecordDescriptorProvider recordDescProvider, int partition,
 			int nPartitions) {
-		return new BTreeDropOperatorNodePushable(bufferCacheProvider, btreeRegistryProvider, btreeFileName, fileMappingProvider);
+		return new BTreeDropOperatorNodePushable(bufferCacheProvider, btreeRegistryProvider, btreeFileName, fileMappingProviderProvider);
 	}	
 }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorNodePushable.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorNodePushable.java
index d0b8c40..9903cdf 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorNodePushable.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorNodePushable.java
@@ -7,18 +7,17 @@
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.common.file.FileManager;
-import edu.uci.ics.hyracks.storage.common.file.IFileMappingProvider;
 
 public class BTreeDropOperatorNodePushable implements IOperatorNodePushable {
 	
 	private String btreeFileName;
 	private IBTreeRegistryProvider btreeRegistryProvider;
 	private IBufferCacheProvider bufferCacheProvider;
-	private IFileMappingProvider fileMappingProvider;
+	private IFileMappingProviderProvider fileMappingProviderProvider;
 	
-	public BTreeDropOperatorNodePushable(IBufferCacheProvider bufferCacheProvider, IBTreeRegistryProvider btreeRegistryProvider, String btreeFileName, IFileMappingProvider fileMappingProvider) {
+	public BTreeDropOperatorNodePushable(IBufferCacheProvider bufferCacheProvider, IBTreeRegistryProvider btreeRegistryProvider, String btreeFileName, IFileMappingProviderProvider fileMappingProviderProvider) {
 		this.btreeFileName = btreeFileName;
-		this.fileMappingProvider = fileMappingProvider;
+		this.fileMappingProviderProvider = fileMappingProviderProvider;
 		this.bufferCacheProvider = bufferCacheProvider;
 		this.btreeRegistryProvider = btreeRegistryProvider;
 	}
@@ -46,7 +45,7 @@
 		String ncDataPath = System.getProperty("NodeControllerDataPath");       
         String fileName = ncDataPath + btreeFileName;
 		
-        int btreeFileId = fileMappingProvider.mapNameToFileId(fileName, false);        
+        int btreeFileId = fileMappingProviderProvider.getFileMappingProvider().mapNameToFileId(fileName, false);        
         
 		// unregister btree instance            
 		btreeRegistry.lock();
@@ -63,6 +62,9 @@
         if (f.exists()) {
 			f.delete();
 		}       
+        
+        // remove name to id mapping
+        fileMappingProviderProvider.getFileMappingProvider().unmapName(fileName);
 	}
 
 	@Override
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorDescriptor.java
index 9118b96..a33fbc7 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorDescriptor.java
@@ -40,12 +40,13 @@
 			IFileSplitProvider fileSplitProvider, RecordDescriptor recDesc,
 			IBufferCacheProvider bufferCacheProvider,
 			IBTreeRegistryProvider btreeRegistryProvider,
-			String btreeFileName, IFileMappingProvider fileMappingProvider, IBTreeInteriorFrameFactory interiorFactory,
+			String btreeFileName, IFileMappingProviderProvider fileMappingProviderProvider, 
+			IBTreeInteriorFrameFactory interiorFactory,
 			IBTreeLeafFrameFactory leafFactory, int fieldCount, 
 			IBinaryComparatorFactory[] comparatorFactories,			
 			int[] fieldPermutation, BTreeOp op) {
 		super(spec, 1, 1, fileSplitProvider, recDesc, bufferCacheProvider,
-				btreeRegistryProvider, btreeFileName, fileMappingProvider, interiorFactory,
+				btreeRegistryProvider, btreeFileName, fileMappingProviderProvider, interiorFactory,
 				leafFactory, fieldCount, comparatorFactories);
 		this.fieldPermutation = fieldPermutation;		
 		this.op = op;
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeOpHelper.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeOpHelper.java
index 64cec29..62d4811 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeOpHelper.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeOpHelper.java
@@ -38,7 +38,6 @@
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.FileInfo;
 import edu.uci.ics.hyracks.storage.common.file.FileManager;
-import edu.uci.ics.hyracks.storage.common.file.IFileMappingProvider;
 
 final class BTreeOpHelper {
     private IBTreeInteriorFrame interiorFrame;
@@ -62,12 +61,12 @@
     	
     	IBufferCache bufferCache = opDesc.getBufferCacheProvider().getBufferCache();
         FileManager fileManager = opDesc.getBufferCacheProvider().getFileManager();
-        IFileMappingProvider fileMappingProvider = opDesc.getFileMappingProvider();
+        IFileMappingProviderProvider fileMappingProviderProvider = opDesc.getFileMappingProviderProvider();
                 
         String ncDataPath = System.getProperty("NodeControllerDataPath");
         String fileName = ncDataPath + opDesc.getBtreeFileName();
         
-        btreeFileId = fileMappingProvider.mapNameToFileId(fileName, createBTree);        
+        btreeFileId = fileMappingProviderProvider.getFileMappingProvider().mapNameToFileId(fileName, createBTree);     
         
         File f = new File(fileName);
         if(!f.exists()) {
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorDescriptor.java
index 1e21510..240776c 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorDescriptor.java
@@ -35,8 +35,8 @@
 	private ITupleReferenceFactory[] searchKeys; // create tuples for low and high keys	
 	private int searchKeyFieldCount;
 	
-	public BTreeSearchOperatorDescriptor(JobSpecification spec, IFileSplitProvider fileSplitProvider, RecordDescriptor recDesc, IBufferCacheProvider bufferCacheProvider, IBTreeRegistryProvider btreeRegistryProvider, String btreeFileName, IFileMappingProvider fileMappingProvider, IBTreeInteriorFrameFactory interiorFactory, IBTreeLeafFrameFactory leafFactory, int fieldCount, IBinaryComparatorFactory[] comparatorFactories, boolean isForward, ITupleReferenceFactory[] searchKeys, int searchKeyFields) {
-		super(spec, 0, 1, fileSplitProvider, recDesc, bufferCacheProvider, btreeRegistryProvider, btreeFileName, fileMappingProvider, interiorFactory, leafFactory, fieldCount, comparatorFactories);
+	public BTreeSearchOperatorDescriptor(JobSpecification spec, IFileSplitProvider fileSplitProvider, RecordDescriptor recDesc, IBufferCacheProvider bufferCacheProvider, IBTreeRegistryProvider btreeRegistryProvider, String btreeFileName, IFileMappingProviderProvider fileMappingProviderProvider, IBTreeInteriorFrameFactory interiorFactory, IBTreeLeafFrameFactory leafFactory, int fieldCount, IBinaryComparatorFactory[] comparatorFactories, boolean isForward, ITupleReferenceFactory[] searchKeys, int searchKeyFields) {
+		super(spec, 0, 1, fileSplitProvider, recDesc, bufferCacheProvider, btreeRegistryProvider, btreeFileName, fileMappingProviderProvider, interiorFactory, leafFactory, fieldCount, comparatorFactories);
 		this.isForward = isForward;
 		this.searchKeys = searchKeys;
 		this.searchKeyFieldCount = searchKeyFields;
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/FileMappingProvider.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/FileMappingProvider.java
index 0d1b9c1..995ed23 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/FileMappingProvider.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/FileMappingProvider.java
@@ -28,4 +28,9 @@
 			return val; // just return value
 		}			
 	}
+
+	@Override
+	public void unmapName(String name) {
+		map.remove(name);
+	}
 }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/FileMappingProviderProvider.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/FileMappingProviderProvider.java
new file mode 100644
index 0000000..edf1898
--- /dev/null
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/FileMappingProviderProvider.java
@@ -0,0 +1,17 @@
+package edu.uci.ics.hyracks.storage.am.btree.dataflow;
+
+import edu.uci.ics.hyracks.storage.common.file.IFileMappingProvider;
+
+public class FileMappingProviderProvider implements IFileMappingProviderProvider {
+	private static final long serialVersionUID = 1L;
+	
+	private static IFileMappingProvider fileMappingProvider = null;
+	
+	@Override
+	public IFileMappingProvider getFileMappingProvider() {
+		if(fileMappingProvider == null) {
+			fileMappingProvider = new FileMappingProvider();
+		}		
+		return fileMappingProvider;
+	}
+}
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/IFileMappingProviderProvider.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/IFileMappingProviderProvider.java
new file mode 100644
index 0000000..b88e058
--- /dev/null
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/IFileMappingProviderProvider.java
@@ -0,0 +1,9 @@
+package edu.uci.ics.hyracks.storage.am.btree.dataflow;
+
+import java.io.Serializable;
+
+import edu.uci.ics.hyracks.storage.common.file.IFileMappingProvider;
+
+public interface IFileMappingProviderProvider extends Serializable {
+	public IFileMappingProvider getFileMappingProvider();
+}