reset arraybackedvaluestorage before using
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/RecordMergeDescriptor.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/RecordMergeDescriptor.java
index 6a8b916..7b2f211 100644
--- a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/RecordMergeDescriptor.java
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/RecordMergeDescriptor.java
@@ -68,7 +68,10 @@
 
                     @Override
                     public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {
+                        abvs0.reset();
+                        abvs1.reset();
                         rb.init();
+
                         eval0.evaluate(tuple);
                         eval1.evaluate(tuple);
                         vp0.set(abvs0);