diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/declared/AqlMetadataProvider.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/declared/AqlMetadataProvider.java
index d29e2c5..17d4b73 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/declared/AqlMetadataProvider.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/declared/AqlMetadataProvider.java
@@ -499,26 +499,29 @@
             }
             int numPrimaryKeys = DatasetUtils.getPartitioningKeys(dataset).size();
             RecordDescriptor outputRecDesc = JobGenHelper.mkRecordDescriptor(typeEnv, opSchema, context);
-            ITypeTraits[] typeTraits = null;
             int[] bloomFilterKeyFields;
             if (isSecondary) {
                 Index secondaryIndex = MetadataManager.INSTANCE.getIndex(mdTxnCtx, dataset.getDataverseName(),
                         dataset.getDatasetName(), indexName);
                 int numSecondaryKeys = secondaryIndex.getKeyFieldNames().size();
-                typeTraits = JobGenHelper.variablesToTypeTraits(outputVars, 0, outputVars.size(), typeEnv, context);
                 bloomFilterKeyFields = new int[numSecondaryKeys];
                 for (int i = 0; i < numSecondaryKeys; i++) {
                     bloomFilterKeyFields[i] = i;
                 }
             } else {
-                typeTraits = JobGenHelper.variablesToTypeTraits(outputVars, 0, outputVars.size(), typeEnv, context);
                 bloomFilterKeyFields = new int[numPrimaryKeys];
                 for (int i = 0; i < numPrimaryKeys; i++) {
                     bloomFilterKeyFields[i] = i;
                 }
             }
-            IBinaryComparatorFactory[] comparatorFactories = JobGenHelper.variablesToAscBinaryComparatorFactories(
-                    outputVars, 0, outputVars.size(), typeEnv, context);
+
+            String itemTypeName = dataset.getItemTypeName();
+            ARecordType itemType = (ARecordType) MetadataManager.INSTANCE.getDatatype(mdTxnCtx,
+                    dataset.getDataverseName(), itemTypeName).getDatatype();
+
+            ITypeTraits[] typeTraits = DatasetUtils.computeTupleTypeTraits(dataset, itemType);
+            IBinaryComparatorFactory[] comparatorFactories = DatasetUtils.computeKeysBinaryComparatorFactories(dataset,
+                    itemType, context.getBinaryComparatorFactoryProvider());
 
             IAsterixApplicationContextInfo appContext = (IAsterixApplicationContextInfo) context.getAppContext();
             Pair<IFileSplitProvider, AlgebricksPartitionConstraint> spPc;