Change cardinality() into a C-code function, instead of a SQL-language

alias for array_length(v,1).  The efficiency gain here is doubtless
negligible --- what I'm interested in is making sure that if we have
second thoughts about the definition, we will not have to force a
post-beta initdb to change the implementation.

src/backend/utils/adt/arrayfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.153 2009/01/30 21:21:18 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.154 2009/04/05 22:28:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1668,6 +1668,28 @@ array_length(PG_FUNCTION_ARGS)
 	PG_RETURN_INT32(result);
 }
 
+/*
+ * array_cardinality :
+ *		SQL-spec alias for array_length(v, 1)
+ */
+Datum
+array_cardinality(PG_FUNCTION_ARGS)
+{
+	ArrayType  *v = PG_GETARG_ARRAYTYPE_P(0);
+	int		   *dimv;
+	int			result;
+
+	/* Sanity check: does it look like an array at all? */
+	if (ARR_NDIM(v) <= 0 || ARR_NDIM(v) > MAXDIM)
+		PG_RETURN_NULL();
+
+	dimv = ARR_DIMS(v);
+
+	result = dimv[0];
+
+	PG_RETURN_INT32(result);
+}
+
 /*
  * array_ref :
  *	  This routine takes an array pointer and a subscript array and returns

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.527 2009/03/31 17:59:56 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.528 2009/04/05 22:28:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200903311
+#define CATALOG_VERSION_NO	200904051
 
 #endif

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.539 2009/03/25 22:19:02 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.540 2009/04/05 22:28:59 tgl Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -1005,8 +1005,8 @@ DATA(insert OID = 2092 (  array_upper	   PGNSP PGUID 12 1 0 0 f f f t f i 2 0 23
 DESCR("array upper dimension");
 DATA(insert OID = 2176 (  array_length     PGNSP PGUID 12 1 0 0 f f f t f i 2 0 23 "2277 23" _null_ _null_ _null_ _null_ array_length _null_ _null_ _null_ ));
 DESCR("array length");
-DATA(insert OID = 2179 (  cardinality      PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "2277" _null_ _null_ _null_ _null_ "select pg_catalog.array_length($1, 1)" _null_ _null_ _null_ ));
-DESCR("array length");
+DATA(insert OID = 2179 (  cardinality      PGNSP PGUID 12 1 0 0 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 f f f f f i 2 0 2277 "2277 2283" _null_ _null_ _null_ _null_ array_push _null_ _null_ _null_ ));
 DESCR("append element onto end of array");
 DATA(insert OID = 379 (  array_prepend	   PGNSP PGUID 12 1 0 0 f f f f f i 2 0 2277 "2283 2277" _null_ _null_ _null_ _null_ array_push _null_ _null_ _null_ ));

src/include/utils/array.h

@@ -49,7 +49,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/array.h,v 1.74 2009/01/01 17:24:02 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/array.h,v 1.75 2009/04/05 22:28:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -200,6 +200,7 @@ extern Datum array_dims(PG_FUNCTION_ARGS);
 extern Datum array_lower(PG_FUNCTION_ARGS);
 extern Datum array_upper(PG_FUNCTION_ARGS);
 extern Datum array_length(PG_FUNCTION_ARGS);
+extern Datum array_cardinality(PG_FUNCTION_ARGS);
 extern Datum array_larger(PG_FUNCTION_ARGS);
 extern Datum array_smaller(PG_FUNCTION_ARGS);
 extern Datum generate_subscripts(PG_FUNCTION_ARGS);