diff --git a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/BTreeAccessMethod.java b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/BTreeAccessMethod.java
index fc50ec5..5132f55 100644
--- a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/BTreeAccessMethod.java
+++ b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/BTreeAccessMethod.java
@@ -155,11 +155,10 @@
         // Determine probe and index subtrees based on chosen index.
         OptimizableOperatorSubTree indexSubTree = null;
         OptimizableOperatorSubTree probeSubTree = null;
-        if (leftSubTree.hasDataSourceScan() && leftSubTree.dataset != null
-                && dataset.getDatasetName().equals(leftSubTree.dataset.getDatasetName())) {
+        if (leftSubTree.hasDataSourceScan() && dataset.getDatasetName().equals(leftSubTree.dataset.getDatasetName())) {
             indexSubTree = leftSubTree;
             probeSubTree = rightSubTree;
-        } else if (rightSubTree.hasDataSourceScan() && rightSubTree.dataset != null
+        } else if (rightSubTree.hasDataSourceScan()
                 && dataset.getDatasetName().equals(rightSubTree.dataset.getDatasetName())) {
             indexSubTree = rightSubTree;
             probeSubTree = leftSubTree;
diff --git a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/InvertedIndexAccessMethod.java b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/InvertedIndexAccessMethod.java
index 9c49783..d73f437 100644
--- a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/InvertedIndexAccessMethod.java
+++ b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/InvertedIndexAccessMethod.java
@@ -416,16 +416,13 @@
         // Determine probe and index subtrees based on chosen index.
         OptimizableOperatorSubTree indexSubTree = null;
         OptimizableOperatorSubTree probeSubTree = null;
-        if (leftSubTree.hasDataSourceScan() && leftSubTree.dataset != null
-                && dataset.getDatasetName().equals(leftSubTree.dataset.getDatasetName())) {
+        if (leftSubTree.hasDataSourceScan() && dataset.getDatasetName().equals(leftSubTree.dataset.getDatasetName())) {
             indexSubTree = leftSubTree;
             probeSubTree = rightSubTree;
-        } else if (rightSubTree.hasDataSourceScan() && rightSubTree.dataset != null
+        } else if (rightSubTree.hasDataSourceScan()
                 && dataset.getDatasetName().equals(rightSubTree.dataset.getDatasetName())) {
             indexSubTree = rightSubTree;
             probeSubTree = leftSubTree;
-        } else {
-            return false;
         }
         IOptimizableFuncExpr optFuncExpr = AccessMethodUtils.chooseFirstOptFuncExpr(chosenIndex, analysisCtx);
         // The arguments of edit-distance-contains() function are asymmetrical, we can only use index if the dataset of index subtree and the dataset of first argument's subtree is the same     
@@ -527,8 +524,7 @@
             ILogicalExpression joinCond, IOptimizableFuncExpr optFuncExpr, List<LogicalVariable> originalSubTreePKs,
             List<LogicalVariable> surrogateSubTreePKs, IOptimizationContext context) throws AlgebricksException {
 
-        AqlMetadataProvider metadataProvider = (AqlMetadataProvider) context.getMetadataProvider();
-        probeSubTree.getPrimaryKeyVars(originalSubTreePKs, metadataProvider);
+        probeSubTree.getPrimaryKeyVars(originalSubTreePKs);
 
         // Create two copies of the original probe subtree.
         // The first copy, which becomes the new probe subtree, will retain the primary-key and secondary-search key variables,
diff --git a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/OptimizableOperatorSubTree.java b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/OptimizableOperatorSubTree.java
index 77dff9f..5c2daa7 100644
--- a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/OptimizableOperatorSubTree.java
+++ b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/OptimizableOperatorSubTree.java
@@ -182,7 +182,7 @@
         recordType = null;
     }
 
-    public void getPrimaryKeyVars(List<LogicalVariable> target, AqlMetadataProvider metadataProvider)
+    public void getPrimaryKeyVars(List<LogicalVariable> target)
             throws AlgebricksException {
         switch (dataSourceType) {
             case DATASOURCE_SCAN:
diff --git a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/RTreeAccessMethod.java b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/RTreeAccessMethod.java
index 9fb658c..7110fbb 100644
--- a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/RTreeAccessMethod.java
+++ b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/am/RTreeAccessMethod.java
@@ -111,11 +111,10 @@
         // Determine probe and index subtrees based on chosen index.
         OptimizableOperatorSubTree indexSubTree = null;
         OptimizableOperatorSubTree probeSubTree = null;
-        if (leftSubTree.hasDataSourceScan() && leftSubTree.dataset != null
-                && dataset.getDatasetName().equals(leftSubTree.dataset.getDatasetName())) {
+        if (leftSubTree.hasDataSourceScan() && dataset.getDatasetName().equals(leftSubTree.dataset.getDatasetName())) {
             indexSubTree = leftSubTree;
             probeSubTree = rightSubTree;
-        } else if (rightSubTree.hasDataSourceScan() && rightSubTree.dataset != null
+        } else if (rightSubTree.hasDataSourceScan()
                 && dataset.getDatasetName().equals(rightSubTree.dataset.getDatasetName())) {
             indexSubTree = rightSubTree;
             probeSubTree = leftSubTree;