diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/AqlTranslator.java b/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/AqlTranslator.java
index 9884486..d8a71b8 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/AqlTranslator.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/AqlTranslator.java
@@ -721,7 +721,6 @@
         String datasetName = stmtCreateIndex.getDatasetName().getValue();
 
         MetadataTransactionContext mdTxnCtx = MetadataManager.INSTANCE.beginTransaction();
-
         boolean bActiveTxn = true;
         metadataProvider.setMetadataTxnContext(mdTxnCtx);
 
@@ -1657,13 +1656,14 @@
 
     private void handleLoadStatement(AqlMetadataProvider metadataProvider, Statement stmt, IHyracksClientConnection hcc)
             throws Exception {
+        LoadStatement loadStmt = (LoadStatement) stmt;
+        String dataverseName = getActiveDataverseName(loadStmt.getDataverseName());
+        String datasetName = loadStmt.getDatasetName().getValue();
         MetadataTransactionContext mdTxnCtx = MetadataManager.INSTANCE.beginTransaction();
         boolean bActiveTxn = true;
         metadataProvider.setMetadataTxnContext(mdTxnCtx);
-        acquireReadLatch();
+        MetadataLockManager.INSTANCE.modifyDatasetBegin(dataverseName, dataverseName + "." + datasetName);
         try {
-            LoadStatement loadStmt = (LoadStatement) stmt;
-            String dataverseName = getActiveDataverseName(loadStmt.getDataverseName());
             CompiledLoadFromFileStatement cls = new CompiledLoadFromFileStatement(dataverseName, loadStmt
                     .getDatasetName().getValue(), loadStmt.getAdapter(), loadStmt.getProperties(),
                     loadStmt.dataIsAlreadySorted());
@@ -1680,7 +1680,7 @@
             }
             throw e;
         } finally {
-            releaseReadLatch();
+            MetadataLockManager.INSTANCE.modifyDatasetEnd(dataverseName, dataverseName + "." + datasetName);
         }
     }
 
@@ -2399,13 +2399,14 @@
     private void handleRunStatement(AqlMetadataProvider metadataProvider, Statement stmt,
             IHyracksClientConnection hcc) throws AsterixException, Exception {
         RunStatement runStmt = (RunStatement) stmt;
-        switch(runStmt.getSystem()) {
+        switch (runStmt.getSystem()) {
             case "pregel":
             case "pregelix":
                 handlePregelixStatement(metadataProvider, runStmt, hcc);
                 break;
             default:
-                throw new AlgebricksException("The system \""+runStmt.getSystem()+"\" specified in your run statement is not supported.");
+                throw new AlgebricksException("The system \"" + runStmt.getSystem()
+                        + "\" specified in your run statement is not supported.");
         }
 
     }
@@ -2588,8 +2589,7 @@
             }
             throw e;
         } finally {
-            MetadataLockManager.INSTANCE
-                    .pregelixEnd(dataverseNameFrom, datasetNameFrom, datasetNameTo);
+            MetadataLockManager.INSTANCE.pregelixEnd(dataverseNameFrom, datasetNameFrom, datasetNameTo);
         }
     }
 
@@ -2657,14 +2657,6 @@
         return getActiveDataverseName(dataverse != null ? dataverse.getValue() : null);
     }
 
-    private void acquireReadLatch() {
-        MetadataManager.INSTANCE.acquireReadLatch();
-    }
-
-    private void releaseReadLatch() {
-        MetadataManager.INSTANCE.releaseReadLatch();
-    }
-
     private void abort(Exception rootE, Exception parentE, MetadataTransactionContext mdTxnCtx) {
         try {
             if (IS_DEBUG_MODE) {
diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/file/ExternalIndexingOperations.java b/asterix-app/src/main/java/edu/uci/ics/asterix/file/ExternalIndexingOperations.java
index 707b7de..da12f14 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/file/ExternalIndexingOperations.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/file/ExternalIndexingOperations.java
@@ -165,7 +165,7 @@
                 FileStatus[] fileStatuses = fs.listStatus(new Path(aPath));
                 for (int i = 0; i < fileStatuses.length; i++) {
                     int nextFileNumber = files.size();
-                    if (fileStatuses[i].isDir()) {
+                    if (fileStatuses[i].isDirectory()) {
                         listSubFiles(dataset, fs, fileStatuses[i], files);
                     } else {
                         files.add(new ExternalFile(dataset.getDataverseName(), dataset.getDatasetName(),
@@ -196,7 +196,7 @@
         FileStatus[] fileStatuses = srcFs.listStatus(path);
         for (int i = 0; i < fileStatuses.length; i++) {
             int nextFileNumber = files.size();
-            if (fileStatuses[i].isDir()) {
+            if (fileStatuses[i].isDirectory()) {
                 listSubFiles(dataset, srcFs, fileStatuses[i], files);
             } else {
                 files.add(new ExternalFile(dataset.getDataverseName(), dataset.getDatasetName(), nextFileNumber,
@@ -267,7 +267,7 @@
         HDFSIndexingAdapterFactory adapterFactory = new HDFSIndexingAdapterFactory();
         adapterFactory.setFiles(files);
         adapterFactory.configure(((ExternalDatasetDetails) dataset.getDatasetDetails()).getProperties(),
-                (ARecordType) itemType, false, null);
+                (ARecordType) itemType);
         return new Pair<ExternalDataScanOperatorDescriptor, AlgebricksPartitionConstraint>(
                 new ExternalDataScanOperatorDescriptor(jobSpec, indexerDesc, adapterFactory),
                 adapterFactory.getPartitionConstraint());
diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryBTreeOperationsHelper.java b/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryBTreeOperationsHelper.java
index 5459a80..9b799d5 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryBTreeOperationsHelper.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryBTreeOperationsHelper.java
@@ -37,9 +37,7 @@
 import edu.uci.ics.hyracks.algebricks.runtime.base.IPushRuntimeFactory;
 import edu.uci.ics.hyracks.algebricks.runtime.operators.base.SinkRuntimeFactory;
 import edu.uci.ics.hyracks.algebricks.runtime.operators.meta.AlgebricksMetaOperatorDescriptor;
-import edu.uci.ics.hyracks.algebricks.runtime.operators.std.EmptyTupleSourceRuntimeFactory;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
-import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractOperatorDescriptor;
@@ -122,9 +120,6 @@
              * and transaction load on dataset referesh
              */
 
-            RecordDescriptor[] rDescs = new RecordDescriptor[] { new RecordDescriptor(new ISerializerDeserializer[] {}) };
-            AlgebricksMetaOperatorDescriptor etsOp = new AlgebricksMetaOperatorDescriptor(spec, 0, 1,
-                    new IPushRuntimeFactory[] { new EmptyTupleSourceRuntimeFactory() }, rDescs);
             // Create external indexing scan operator
             ExternalDataScanOperatorDescriptor primaryScanOp = createExternalIndexingOp(spec);
 
@@ -165,10 +160,6 @@
                 spec.connect(new OneToOneConnectorDescriptor(spec), secondaryBulkLoadOp, 0, metaOp, 0);
                 root = metaOp;
             }
-            AlgebricksPartitionConstraintHelper
-                    .setPartitionConstraintInJobSpec(spec, etsOp, primaryPartitionConstraint);
-            // Connect the operators.
-            spec.connect(new OneToOneConnectorDescriptor(spec), etsOp, 0, primaryScanOp, 0);
             spec.connect(new OneToOneConnectorDescriptor(spec), primaryScanOp, 0, asterixAssignOp, 0);
             if (anySecondaryKeyIsNullable) {
                 spec.connect(new OneToOneConnectorDescriptor(spec), asterixAssignOp, 0, selectOp, 0);
diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryRTreeOperationsHelper.java b/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryRTreeOperationsHelper.java
index 1f48509..409371a 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryRTreeOperationsHelper.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryRTreeOperationsHelper.java
@@ -50,7 +50,6 @@
 import edu.uci.ics.hyracks.algebricks.runtime.base.IPushRuntimeFactory;
 import edu.uci.ics.hyracks.algebricks.runtime.operators.base.SinkRuntimeFactory;
 import edu.uci.ics.hyracks.algebricks.runtime.operators.meta.AlgebricksMetaOperatorDescriptor;
-import edu.uci.ics.hyracks.algebricks.runtime.operators.std.EmptyTupleSourceRuntimeFactory;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
@@ -281,9 +280,6 @@
              * In case of external data, this method is used to build loading jobs for both initial load on index creation
              * and transaction load on dataset referesh
              */
-            RecordDescriptor[] rDescs = new RecordDescriptor[] { new RecordDescriptor(new ISerializerDeserializer[] {}) };
-            AlgebricksMetaOperatorDescriptor etsOp = new AlgebricksMetaOperatorDescriptor(spec, 0, 1,
-                    new IPushRuntimeFactory[] { new EmptyTupleSourceRuntimeFactory() }, rDescs);
             // Create external indexing scan operator
             ExternalDataScanOperatorDescriptor primaryScanOp = createExternalIndexingOp(spec);
             // Assign op.
@@ -327,10 +323,7 @@
                 spec.connect(new OneToOneConnectorDescriptor(spec), secondaryBulkLoadOp, 0, metaOp, 0);
                 root = metaOp;
             }
-            AlgebricksPartitionConstraintHelper
-                    .setPartitionConstraintInJobSpec(spec, etsOp, primaryPartitionConstraint);
-            // Connect the operators.
-            spec.connect(new OneToOneConnectorDescriptor(spec), etsOp, 0, primaryScanOp, 0);
+
             spec.connect(new OneToOneConnectorDescriptor(spec), primaryScanOp, 0, asterixAssignOp, 0);
             if (anySecondaryKeyIsNullable) {
                 spec.connect(new OneToOneConnectorDescriptor(spec), asterixAssignOp, 0, selectOp, 0);
diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/CCApplicationEntryPoint.java b/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/CCApplicationEntryPoint.java
index af7e511..1320629 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/CCApplicationEntryPoint.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/CCApplicationEntryPoint.java
@@ -20,6 +20,7 @@
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.servlet.ServletContextHandler;
 import org.eclipse.jetty.servlet.ServletHolder;
+import org.eclipse.jetty.util.component.AbstractLifeCycle;
 
 import edu.uci.ics.asterix.api.http.servlet.APIServlet;
 import edu.uci.ics.asterix.api.http.servlet.AQLAPIServlet;
@@ -87,6 +88,10 @@
 
         setupFeedServer(externalProperties);
         feedServer.start();
+        
+        waitUntilServerStart(webServer);
+        waitUntilServerStart(jsonAPIServer);
+        waitUntilServerStart(feedServer);
 
         AsterixGlobalRecoveryManager.INSTANCE = new AsterixGlobalRecoveryManager(
                 (HyracksConnection) getNewHyracksClientConnection());
@@ -95,6 +100,15 @@
         ccAppCtx.addClusterLifecycleListener(ClusterLifecycleListener.INSTANCE);
     }
 
+    private void waitUntilServerStart(AbstractLifeCycle webServer) throws Exception{
+        while(!webServer.isStarted()){
+            if(webServer.isFailed()){
+                throw new Exception("Server failed to start");
+            }
+            wait(1000);
+        }
+    }
+
     @Override
     public void stop() throws Exception {
         if (LOGGER.isLoggable(Level.INFO)) {
diff --git a/asterix-app/src/test/resources/optimizerts/results/consolidate-selects-complex.plan b/asterix-app/src/test/resources/optimizerts/results/consolidate-selects-complex.plan
index f8bd22d..3abde90 100644
--- a/asterix-app/src/test/resources/optimizerts/results/consolidate-selects-complex.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/consolidate-selects-complex.plan
@@ -3,10 +3,12 @@
     -- STREAM_PROJECT  |PARTITIONED|
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         -- BULKLOAD  |PARTITIONED|
-          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$1(ASC)] HASH:[$$1]  |PARTITIONED|
-            -- DATASOURCE_SCAN  |PARTITIONED|
+          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$2(ASC)] HASH:[$$2]  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 -- DISTRIBUTE_RESULT  |PARTITIONED|
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive-open_01.plan b/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive-open_01.plan
index 9d2d60b..3fbd339 100644
--- a/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive-open_01.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive-open_01.plan
@@ -3,10 +3,12 @@
     -- STREAM_PROJECT  |PARTITIONED|
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         -- BULKLOAD  |PARTITIONED|
-          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$1(ASC)] HASH:[$$1]  |PARTITIONED|
-            -- DATASOURCE_SCAN  |PARTITIONED|
+          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$2(ASC)] HASH:[$$2]  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 -- DISTRIBUTE_RESULT  |PARTITIONED|
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive-open_02.plan b/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive-open_02.plan
index 8cad02f..e3baddf 100644
--- a/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive-open_02.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive-open_02.plan
@@ -3,10 +3,12 @@
     -- STREAM_PROJECT  |PARTITIONED|
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         -- BULKLOAD  |PARTITIONED|
-          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$1(ASC)] HASH:[$$1]  |PARTITIONED|
-            -- DATASOURCE_SCAN  |PARTITIONED|
+          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$2(ASC)] HASH:[$$2]  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 -- DISTRIBUTE_RESULT  |PARTITIONED|
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive_01.plan b/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive_01.plan
index 9d2d60b..3fbd339 100644
--- a/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive_01.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive_01.plan
@@ -3,10 +3,12 @@
     -- STREAM_PROJECT  |PARTITIONED|
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         -- BULKLOAD  |PARTITIONED|
-          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$1(ASC)] HASH:[$$1]  |PARTITIONED|
-            -- DATASOURCE_SCAN  |PARTITIONED|
+          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$2(ASC)] HASH:[$$2]  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 -- DISTRIBUTE_RESULT  |PARTITIONED|
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive_02.plan b/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive_02.plan
index 8cad02f..e3baddf 100644
--- a/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive_02.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/orders-index-search-conjunctive_02.plan
@@ -3,10 +3,12 @@
     -- STREAM_PROJECT  |PARTITIONED|
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         -- BULKLOAD  |PARTITIONED|
-          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$1(ASC)] HASH:[$$1]  |PARTITIONED|
-            -- DATASOURCE_SCAN  |PARTITIONED|
+          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$2(ASC)] HASH:[$$2]  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 -- DISTRIBUTE_RESULT  |PARTITIONED|
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/q01_pricing_summary_report_nt.plan b/asterix-app/src/test/resources/optimizerts/results/q01_pricing_summary_report_nt.plan
index 97c7b80..fb35c0c 100644
--- a/asterix-app/src/test/resources/optimizerts/results/q01_pricing_summary_report_nt.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/q01_pricing_summary_report_nt.plan
@@ -3,10 +3,12 @@
     -- STREAM_PROJECT  |PARTITIONED|
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         -- BULKLOAD  |PARTITIONED|
-          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$1(ASC), $$2(ASC)] HASH:[$$1, $$2]  |PARTITIONED|
-            -- DATASOURCE_SCAN  |PARTITIONED|
+          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$2(ASC), $$3(ASC)] HASH:[$$2, $$3]  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 -- DISTRIBUTE_RESULT  |PARTITIONED|
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/rtree-secondary-index-open.plan b/asterix-app/src/test/resources/optimizerts/results/rtree-secondary-index-open.plan
index d86e4f5..f77dc35 100644
--- a/asterix-app/src/test/resources/optimizerts/results/rtree-secondary-index-open.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/rtree-secondary-index-open.plan
@@ -3,10 +3,12 @@
     -- STREAM_PROJECT  |PARTITIONED|
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         -- BULKLOAD  |PARTITIONED|
-          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$1(ASC)] HASH:[$$1]  |PARTITIONED|
-            -- DATASOURCE_SCAN  |PARTITIONED|
+          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$2(ASC)] HASH:[$$2]  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 -- DISTRIBUTE_RESULT  |PARTITIONED|
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/rtree-secondary-index.plan b/asterix-app/src/test/resources/optimizerts/results/rtree-secondary-index.plan
index d86e4f5..f77dc35 100644
--- a/asterix-app/src/test/resources/optimizerts/results/rtree-secondary-index.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/rtree-secondary-index.plan
@@ -3,10 +3,12 @@
     -- STREAM_PROJECT  |PARTITIONED|
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         -- BULKLOAD  |PARTITIONED|
-          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$1(ASC)] HASH:[$$1]  |PARTITIONED|
-            -- DATASOURCE_SCAN  |PARTITIONED|
+          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$2(ASC)] HASH:[$$2]  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 -- DISTRIBUTE_RESULT  |PARTITIONED|
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/scan-delete-rtree-secondary-index.plan b/asterix-app/src/test/resources/optimizerts/results/scan-delete-rtree-secondary-index.plan
index 83a29cc..2d3d8fc 100644
--- a/asterix-app/src/test/resources/optimizerts/results/scan-delete-rtree-secondary-index.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/scan-delete-rtree-secondary-index.plan
@@ -3,10 +3,12 @@
     -- STREAM_PROJECT  |PARTITIONED|
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         -- BULKLOAD  |PARTITIONED|
-          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$1(ASC)] HASH:[$$1]  |PARTITIONED|
-            -- DATASOURCE_SCAN  |PARTITIONED|
+          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$2(ASC)] HASH:[$$2]  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 -- COMMIT  |PARTITIONED|
   -- STREAM_PROJECT  |PARTITIONED|
     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/skip-index/skip-rtree-secondary-index.plan b/asterix-app/src/test/resources/optimizerts/results/skip-index/skip-rtree-secondary-index.plan
index 25b65de..1534f6c 100644
--- a/asterix-app/src/test/resources/optimizerts/results/skip-index/skip-rtree-secondary-index.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/skip-index/skip-rtree-secondary-index.plan
@@ -3,10 +3,12 @@
     -- STREAM_PROJECT  |PARTITIONED|
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         -- BULKLOAD  |PARTITIONED|
-          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$1(ASC)] HASH:[$$1]  |PARTITIONED|
-            -- DATASOURCE_SCAN  |PARTITIONED|
+          -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$2(ASC)] HASH:[$$2]  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 -- DISTRIBUTE_RESULT  |PARTITIONED|
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|