diff --git a/src/backend/utils/adt/array_userfuncs.c b/src/backend/utils/adt/array_userfuncs.c
index 600646e834..5c20d0c9d0 100644
--- a/src/backend/utils/adt/array_userfuncs.c
+++ b/src/backend/utils/adt/array_userfuncs.c
@@ -17,101 +17,98 @@
 #include "utils/lsyscache.h"
 
 
+/*
+ * fetch_array_arg_replace_nulls
+ *
+ * Fetch an array-valued argument; if it's null, construct an empty array
+ * value of the proper data type.  Also cache basic element type information
+ * in fn_extra.
+ */
+static ArrayType *
+fetch_array_arg_replace_nulls(FunctionCallInfo fcinfo, int argno)
+{
+	ArrayType  *v;
+	ArrayMetaState *my_extra;
+
+	my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
+	if (my_extra == NULL)
+	{
+		/* First time through, so look up the array type and element type */
+		Oid			arr_typeid = get_fn_expr_argtype(fcinfo->flinfo, argno);
+		Oid			element_type;
+
+		if (!OidIsValid(arr_typeid))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("could not determine input data type")));
+		element_type = get_element_type(arr_typeid);
+		if (!OidIsValid(element_type))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("input data type is not an array")));
+
+		my_extra = (ArrayMetaState *)
+			MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
+							   sizeof(ArrayMetaState));
+		my_extra->element_type = element_type;
+
+		/* Cache info about element type */
+		get_typlenbyvalalign(element_type,
+							 &my_extra->typlen,
+							 &my_extra->typbyval,
+							 &my_extra->typalign);
+
+		fcinfo->flinfo->fn_extra = my_extra;
+	}
+
+	/* Now we can collect the array value */
+	if (PG_ARGISNULL(argno))
+		v = construct_empty_array(my_extra->element_type);
+	else
+		v = PG_GETARG_ARRAYTYPE_P(argno);
+
+	return v;
+}
+
 /*-----------------------------------------------------------------------------
- * array_push :
- *		push an element onto either end of a one-dimensional array
+ * array_append :
+ *		push an element onto the end of a one-dimensional array
  *----------------------------------------------------------------------------
  */
 Datum
-array_push(PG_FUNCTION_ARGS)
+array_append(PG_FUNCTION_ARGS)
 {
 	ArrayType  *v;
 	Datum		newelem;
 	bool		isNull;
+	ArrayType  *result;
 	int		   *dimv,
 			   *lb;
-	ArrayType  *result;
 	int			indx;
-	Oid			element_type;
-	int16		typlen;
-	bool		typbyval;
-	char		typalign;
-	Oid			arg0_typeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	Oid			arg1_typeid = get_fn_expr_argtype(fcinfo->flinfo, 1);
-	Oid			arg0_elemid;
-	Oid			arg1_elemid;
 	ArrayMetaState *my_extra;
 
-	if (arg0_typeid == InvalidOid || arg1_typeid == InvalidOid)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("could not determine input data types")));
-
-	arg0_elemid = get_element_type(arg0_typeid);
-	arg1_elemid = get_element_type(arg1_typeid);
-
-	if (arg0_elemid != InvalidOid)
-	{
-		if (PG_ARGISNULL(0))
-			v = construct_empty_array(arg0_elemid);
-		else
-			v = PG_GETARG_ARRAYTYPE_P(0);
-		isNull = PG_ARGISNULL(1);
-		if (isNull)
-			newelem = (Datum) 0;
-		else
-			newelem = PG_GETARG_DATUM(1);
-	}
-	else if (arg1_elemid != InvalidOid)
-	{
-		if (PG_ARGISNULL(1))
-			v = construct_empty_array(arg1_elemid);
-		else
-			v = PG_GETARG_ARRAYTYPE_P(1);
-		isNull = PG_ARGISNULL(0);
-		if (isNull)
-			newelem = (Datum) 0;
-		else
-			newelem = PG_GETARG_DATUM(0);
-	}
+	v = fetch_array_arg_replace_nulls(fcinfo, 0);
+	isNull = PG_ARGISNULL(1);
+	if (isNull)
+		newelem = (Datum) 0;
 	else
-	{
-		/* Shouldn't get here given proper type checking in parser */
-		ereport(ERROR,
-				(errcode(ERRCODE_DATATYPE_MISMATCH),
-				 errmsg("neither input type is an array")));
-		PG_RETURN_NULL();		/* keep compiler quiet */
-	}
-
-	element_type = ARR_ELEMTYPE(v);
+		newelem = PG_GETARG_DATUM(1);
 
 	if (ARR_NDIM(v) == 1)
 	{
+		/* append newelem */
+		int			ub;
+
 		lb = ARR_LBOUND(v);
 		dimv = ARR_DIMS(v);
+		ub = dimv[0] + lb[0] - 1;
+		indx = ub + 1;
 
-		if (arg0_elemid != InvalidOid)
-		{
-			/* append newelem */
-			int			ub = dimv[0] + lb[0] - 1;
-
-			indx = ub + 1;
-			/* overflow? */
-			if (indx < ub)
-				ereport(ERROR,
-						(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
-						 errmsg("integer out of range")));
-		}
-		else
-		{
-			/* prepend newelem */
-			indx = lb[0] - 1;
-			/* overflow? */
-			if (indx > lb[0])
-				ereport(ERROR,
-						(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
-						 errmsg("integer out of range")));
-		}
+		/* overflow? */
+		if (indx < ub)
+			ereport(ERROR,
+					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+					 errmsg("integer out of range")));
 	}
 	else if (ARR_NDIM(v) == 0)
 		indx = 1;
@@ -120,39 +117,66 @@ array_push(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATA_EXCEPTION),
 				 errmsg("argument must be empty or one-dimensional array")));
 
-	/*
-	 * We arrange to look up info about element type only once per series of
-	 * calls, assuming the element type doesn't change underneath us.
-	 */
+	/* Perform element insertion */
 	my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
-	if (my_extra == NULL)
-	{
-		fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
-													  sizeof(ArrayMetaState));
-		my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
-		my_extra->element_type = ~element_type;
-	}
-
-	if (my_extra->element_type != element_type)
-	{
-		/* Get info about element type */
-		get_typlenbyvalalign(element_type,
-							 &my_extra->typlen,
-							 &my_extra->typbyval,
-							 &my_extra->typalign);
-		my_extra->element_type = element_type;
-	}
-	typlen = my_extra->typlen;
-	typbyval = my_extra->typbyval;
-	typalign = my_extra->typalign;
 
 	result = array_set(v, 1, &indx, newelem, isNull,
-					   -1, typlen, typbyval, typalign);
+			   -1, my_extra->typlen, my_extra->typbyval, my_extra->typalign);
 
-	/*
-	 * Readjust result's LB to match the input's.  This does nothing in the
-	 * append case, but it's the simplest way to implement the prepend case.
-	 */
+	PG_RETURN_ARRAYTYPE_P(result);
+}
+
+/*-----------------------------------------------------------------------------
+ * array_prepend :
+ *		push an element onto the front of a one-dimensional array
+ *----------------------------------------------------------------------------
+ */
+Datum
+array_prepend(PG_FUNCTION_ARGS)
+{
+	ArrayType  *v;
+	Datum		newelem;
+	bool		isNull;
+	ArrayType  *result;
+	int		   *dimv,
+			   *lb;
+	int			indx;
+	ArrayMetaState *my_extra;
+
+	isNull = PG_ARGISNULL(0);
+	if (isNull)
+		newelem = (Datum) 0;
+	else
+		newelem = PG_GETARG_DATUM(0);
+	v = fetch_array_arg_replace_nulls(fcinfo, 1);
+
+	if (ARR_NDIM(v) == 1)
+	{
+		/* prepend newelem */
+		lb = ARR_LBOUND(v);
+		dimv = ARR_DIMS(v);
+		indx = lb[0] - 1;
+
+		/* overflow? */
+		if (indx > lb[0])
+			ereport(ERROR,
+					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+					 errmsg("integer out of range")));
+	}
+	else if (ARR_NDIM(v) == 0)
+		indx = 1;
+	else
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("argument must be empty or one-dimensional array")));
+
+	/* Perform element insertion */
+	my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
+
+	result = array_set(v, 1, &indx, newelem, isNull,
+			   -1, my_extra->typlen, my_extra->typbyval, my_extra->typalign);
+
+	/* Readjust result's LB to match the input's, as expected for prepend */
 	if (ARR_NDIM(v) == 1)
 		ARR_LBOUND(result)[0] = ARR_LBOUND(v)[0];
 
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 2b7a0bb93b..9100910c5e 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201501281
+#define CATALOG_VERSION_NO	201502181
 
 #endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 9edfdb8fa8..7ddb473564 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -878,9 +878,9 @@ DATA(insert OID = 2176 (  array_length	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2
 DESCR("array length");
 DATA(insert OID = 3179 (  cardinality	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 23 "2277" _null_ _null_ _null_ _null_ array_cardinality _null_ _null_ _null_ ));
 DESCR("array cardinality");
-DATA(insert OID = 378 (  array_append	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2277 "2277 2283" _null_ _null_ _null_ _null_ array_push _null_ _null_ _null_ ));
+DATA(insert OID = 378 (  array_append	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2277 "2277 2283" _null_ _null_ _null_ _null_ array_append _null_ _null_ _null_ ));
 DESCR("append element onto end of array");
-DATA(insert OID = 379 (  array_prepend	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2277 "2283 2277" _null_ _null_ _null_ _null_ array_push _null_ _null_ _null_ ));
+DATA(insert OID = 379 (  array_prepend	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2277 "2283 2277" _null_ _null_ _null_ _null_ array_prepend _null_ _null_ _null_ ));
 DESCR("prepend element onto front of array");
 DATA(insert OID = 383 (  array_cat		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2277 "2277 2277" _null_ _null_ _null_ _null_ array_cat _null_ _null_ _null_ ));
 DATA(insert OID = 394 (  string_to_array   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 1009 "25 25" _null_ _null_ _null_ _null_ text_to_array _null_ _null_ _null_ ));
diff --git a/src/include/utils/array.h b/src/include/utils/array.h
index dff69eba06..d9fac807f8 100644
--- a/src/include/utils/array.h
+++ b/src/include/utils/array.h
@@ -341,7 +341,8 @@ extern int32 *ArrayGetIntegerTypmods(ArrayType *arr, int *n);
 /*
  * prototypes for functions defined in array_userfuncs.c
  */
-extern Datum array_push(PG_FUNCTION_ARGS);
+extern Datum array_append(PG_FUNCTION_ARGS);
+extern Datum array_prepend(PG_FUNCTION_ARGS);
 extern Datum array_cat(PG_FUNCTION_ARGS);
 
 extern ArrayType *create_singleton_array(FunctionCallInfo fcinfo,
diff --git a/src/test/regress/expected/opr_sanity.out b/src/test/regress/expected/opr_sanity.out
index 9870bfaa01..6b248f2801 100644
--- a/src/test/regress/expected/opr_sanity.out
+++ b/src/test/regress/expected/opr_sanity.out
@@ -176,8 +176,7 @@ ORDER BY 1, 2;
           25 |        1043
         1114 |        1184
         1560 |        1562
-        2277 |        2283
-(5 rows)
+(4 rows)
 
 SELECT DISTINCT p1.proargtypes[1], p2.proargtypes[1]
 FROM pg_proc AS p1, pg_proc AS p2
@@ -194,8 +193,7 @@ ORDER BY 1, 2;
           23 |          28
         1114 |        1184
         1560 |        1562
-        2277 |        2283
-(4 rows)
+(3 rows)
 
 SELECT DISTINCT p1.proargtypes[2], p2.proargtypes[2]
 FROM pg_proc AS p1, pg_proc AS p2