From ac43756dac605549ad05abc154b9ba2b42d80739 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 5 Apr 2009 22:28:59 +0000
Subject: [PATCH] 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 | 22 ++++++++++++++++++++++
 src/include/catalog/catversion.h   |  2 +-
 src/include/catalog/pg_proc.h      |  4 ++--
 src/include/utils/array.h          |  1 +
 4 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index 85f860a32a..b94eae228f 100644
--- a/src/backend/utils/adt/arrayfuncs.c
+++ b/src/backend/utils/adt/arrayfuncs.c
@@ -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
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 74f06d54ca..05305b7dff 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200903311
+#define CATALOG_VERSION_NO	200904051
 
 #endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 61d24c8690..1f4ecb038b 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -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_ ));
diff --git a/src/include/utils/array.h b/src/include/utils/array.h
index 24f8f32b65..d49c5f3ef3 100644
--- a/src/include/utils/array.h
+++ b/src/include/utils/array.h
@@ -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);
-- 
2.39.5