diff --git a/src/test/regress/expected/test_setup.out b/src/test/regress/expected/test_setup.out
index 5d9e6bf12b..3d0eeec996 100644
--- a/src/test/regress/expected/test_setup.out
+++ b/src/test/regress/expected/test_setup.out
@@ -209,10 +209,6 @@ CREATE FUNCTION ttdummy ()
     RETURNS trigger
     AS :'regresslib'
     LANGUAGE C;
-CREATE FUNCTION get_columns_length(oid[])
-    RETURNS int
-    AS :'regresslib'
-    LANGUAGE C STRICT STABLE PARALLEL SAFE;
 -- Use hand-rolled hash functions and operator classes to get predictable
 -- result on different machines.  The hash function for int4 simply returns
 -- the sum of the values passed to it and the one for text returns the length
diff --git a/src/test/regress/regress.c b/src/test/regress/regress.c
index a17afc98be..deffaea578 100644
--- a/src/test/regress/regress.c
+++ b/src/test/regress/regress.c
@@ -42,7 +42,6 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/geo_decls.h"
-#include "utils/lsyscache.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/typcache.h"
@@ -1222,43 +1221,3 @@ binary_coercible(PG_FUNCTION_ARGS)
 
 	PG_RETURN_BOOL(IsBinaryCoercible(srctype, targettype));
 }
-
-/*
- * Return the length of the portion of a tuple consisting of the given array
- * of data types.  The input data types must be fixed-length data types.
- */
-PG_FUNCTION_INFO_V1(get_columns_length);
-Datum
-get_columns_length(PG_FUNCTION_ARGS)
-{
-	ArrayType  *ta = PG_GETARG_ARRAYTYPE_P(0);
-	Oid		   *type_oids;
-	int			ntypes;
-	int			column_offset = 0;
-
-	if (ARR_HASNULL(ta) && array_contains_nulls(ta))
-		elog(ERROR, "argument must not contain nulls");
-
-	if (ARR_NDIM(ta) > 1)
-		elog(ERROR, "argument must be empty or one-dimensional array");
-
-	type_oids = (Oid *) ARR_DATA_PTR(ta);
-	ntypes = ArrayGetNItems(ARR_NDIM(ta), ARR_DIMS(ta));
-	for (int i = 0; i < ntypes; i++)
-	{
-		Oid			typeoid = type_oids[i];
-		int16		typlen;
-		bool		typbyval;
-		char		typalign;
-
-		get_typlenbyvalalign(typeoid, &typlen, &typbyval, &typalign);
-
-		/* the data type must be fixed-length */
-		if (typlen < 0)
-			elog(ERROR, "type %u is not fixed-length data type", typeoid);
-
-		column_offset = att_align_nominal(column_offset + typlen, typalign);
-	}
-
-	PG_RETURN_INT32(column_offset);
-}
diff --git a/src/test/regress/sql/test_setup.sql b/src/test/regress/sql/test_setup.sql
index 1b2d434683..06b0e2121f 100644
--- a/src/test/regress/sql/test_setup.sql
+++ b/src/test/regress/sql/test_setup.sql
@@ -257,11 +257,6 @@ CREATE FUNCTION ttdummy ()
     AS :'regresslib'
     LANGUAGE C;
 
-CREATE FUNCTION get_columns_length(oid[])
-    RETURNS int
-    AS :'regresslib'
-    LANGUAGE C STRICT STABLE PARALLEL SAFE;
-
 -- Use hand-rolled hash functions and operator classes to get predictable
 -- result on different machines.  The hash function for int4 simply returns
 -- the sum of the values passed to it and the one for text returns the length