diff --git a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/IntroduceMaterializationForInsertWithSelfScanRule.java b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/IntroduceMaterializationForInsertWithSelfScanRule.java
index c15b0f0..dd65d94 100644
--- a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/IntroduceMaterializationForInsertWithSelfScanRule.java
+++ b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/IntroduceMaterializationForInsertWithSelfScanRule.java
@@ -23,6 +23,7 @@
 import edu.uci.ics.asterix.metadata.declared.AqlDataSource.AqlDataSourceType;
 import edu.uci.ics.asterix.om.functions.AsterixBuiltinFunctions;
 import edu.uci.ics.asterix.optimizer.rules.am.AccessMethodJobGenParams;
+import edu.uci.ics.asterix.metadata.declared.DatasetDataSource;
 import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
 import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
 import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
@@ -54,7 +55,7 @@
         }
 
         InsertDeleteOperator insertOp = (InsertDeleteOperator) op;
-        boolean sameDataset = checkIfInsertAndScanDatasetsSame(op, ((AqlDataSource) insertOp.getDataSource())
+        boolean sameDataset = checkIfInsertAndScanDatasetsSame(op, ((DatasetDataSource) insertOp.getDataSource())
                 .getDataset().getDatasetName());
 
         if (sameDataset) {
@@ -104,9 +105,8 @@
             } else if (descendantOp.getOperatorTag() == LogicalOperatorTag.DATASOURCESCAN) {
                 DataSourceScanOperator dataSourceScanOp = (DataSourceScanOperator) descendantOp;
                 AqlDataSource ds = (AqlDataSource) dataSourceScanOp.getDataSource();
-                if (ds.getDatasourceType() != AqlDataSourceType.FEED
-                        && ds.getDatasourceType() != AqlDataSourceType.EXTERNAL_FEED) {
-                    if (ds.getDataset().getDatasetName().compareTo(insertDatasetName) == 0) {
+                if (ds.getDatasourceType() != AqlDataSourceType.FEED) {
+                    if ( ((DatasetDataSource)ds).getDataset().getDatasetName().compareTo(insertDatasetName) == 0) {
                         return true;
                     }
                 }
diff --git a/asterix-aql/src/main/javacc/AQL.jj b/asterix-aql/src/main/javacc/AQL.jj
index 8b46dc2..2e1bc6b 100644
--- a/asterix-aql/src/main/javacc/AQL.jj
+++ b/asterix-aql/src/main/javacc/AQL.jj
@@ -1050,7 +1050,7 @@
   boolean secondAfterDot = false;
 }
 {
-  first = Identifier() ( "." second = Identifier()
+  first = Identifier() ( <DOT> second = Identifier()
     {
       secondAfterDot = true;
     }