Change the parameter_types column of the pg_prepared_statements to be

an array of regtype, rather than an array of OIDs. This is likely to
be more useful to user, and the type OID can easily be obtained by
casting a regtype value to OID. Per suggestion from Tom.

Update the documentation and regression tests, and bump the catversion.

src/backend/catalog/system_views.sql

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 1996-2005, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.23 2006/01/08 07:00:25 neilc Exp $
+ * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.24 2006/01/16 18:15:30 neilc Exp $
  */
 
 CREATE VIEW pg_roles AS 
@@ -160,7 +160,7 @@ CREATE VIEW pg_prepared_statements AS
     SELECT P.name, P.statement, P.prepare_time, P.parameter_types, P.from_sql
     FROM pg_prepared_statement() AS P
     (name text, statement text, prepare_time timestamptz,
-     parameter_types oid[], from_sql boolean);
+     parameter_types regtype[], from_sql boolean);
 
 CREATE VIEW pg_settings AS 
     SELECT * 

src/backend/commands/prepare.c

@@ -10,7 +10,7 @@
  * Copyright (c) 2002-2005, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.45 2006/01/08 07:00:25 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.46 2006/01/16 18:15:30 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -45,7 +45,7 @@ static HTAB *prepared_queries = NULL;
 static void InitQueryHashTable(void);
 static ParamListInfo EvaluateParams(EState *estate,
 			   List *params, List *argtypes);
-static Datum build_oid_array(List *oid_list);
+static Datum build_regtype_array(List *oid_list);
 
 /*
  * Implements the 'PREPARE' utility statement.
@@ -674,7 +674,7 @@ ExplainExecuteQuery(ExplainStmt *stmt, ParamListInfo params,
 
 /*
  * This set returning function reads all the prepared statements and
- * returns a set of (name, statement, prepare_time, param_types).
+ * returns a set of (name, statement, prepare_time, param_types, from_sql).
  */
 Datum
 pg_prepared_statement(PG_FUNCTION_ARGS)
@@ -721,7 +721,7 @@ pg_prepared_statement(PG_FUNCTION_ARGS)
 		TupleDescInitEntry(tupdesc, (AttrNumber) 3, "prepare_time",
 						   TIMESTAMPTZOID, -1, 0);
 		TupleDescInitEntry(tupdesc, (AttrNumber) 4, "parameter_types",
-						   OIDARRAYOID, -1, 0);
+						   REGTYPEARRAYOID, -1, 0);
 		TupleDescInitEntry(tupdesc, (AttrNumber) 5, "from_sql",
 						   BOOLOID, -1, 0);
 
@@ -757,7 +757,7 @@ pg_prepared_statement(PG_FUNCTION_ARGS)
 									CStringGetDatum(prep_stmt->query_string));
 
 		values[2] = TimestampTzGetDatum(prep_stmt->prepare_time);
-		values[3] = build_oid_array(prep_stmt->argtype_list);
+		values[3] = build_regtype_array(prep_stmt->argtype_list);
 		values[4] = BoolGetDatum(prep_stmt->from_sql);
 
 		tuple = heap_form_tuple(funcctx->tuple_desc, values, nulls);
@@ -770,26 +770,33 @@ pg_prepared_statement(PG_FUNCTION_ARGS)
 
 /*
  * This utility function takes a List of Oids, and returns a Datum
- * pointing to a Postgres array containing those OIDs. The empty list
- * is returned as a zero-element array, not NULL.
+ * pointing to a one-dimensional Postgres array of regtypes. The empty
+ * list is returned as a zero-element array, not NULL.
  */
 static Datum
-build_oid_array(List *oid_list)
+build_regtype_array(List *oid_list)
 {
 	ListCell   *lc;
 	int			len;
 	int			i;
 	Datum	   *tmp_ary;
-	ArrayType *ary;
+	ArrayType  *result;
 
 	len = list_length(oid_list);
 	tmp_ary = (Datum *) palloc(len * sizeof(Datum));
 
 	i = 0;
 	foreach(lc, oid_list)
-		tmp_ary[i++] = ObjectIdGetDatum(lfirst_oid(lc));
+	{
+		Oid		oid;
+		Datum	oid_str;
+
+		oid = lfirst_oid(lc);
+		oid_str = DirectFunctionCall1(oidout, ObjectIdGetDatum(oid));
+		tmp_ary[i++] = DirectFunctionCall1(regtypein, oid_str);
+	}
 
-	/* XXX: this hardcodes assumptions about the OID type... */
-	ary = construct_array(tmp_ary, len, OIDOID, sizeof(Oid), true, 'i');
-	return PointerGetDatum(ary);
+	/* XXX: this hardcodes assumptions about the regtype type */
+	result = construct_array(tmp_ary, len, REGTYPEOID, 4, true, 'i');
+	return PointerGetDatum(result);
 }

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.310 2006/01/11 20:12:39 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.311 2006/01/16 18:15:30 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200601111
+#define CATALOG_VERSION_NO	200601161
 
 #endif

src/include/catalog/pg_type.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_type.h,v 1.168 2006/01/08 07:00:26 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_type.h,v 1.169 2006/01/16 18:15:30 neilc Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -406,7 +406,6 @@ DATA(insert OID = 1007 (  _int4		 PGNSP PGUID -1 f b t \054 0	23 array_in array_
 DATA(insert OID = 1008 (  _regproc	 PGNSP PGUID -1 f b t \054 0	24 array_in array_out array_recv array_send - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 1009 (  _text		 PGNSP PGUID -1 f b t \054 0	25 array_in array_out array_recv array_send - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 1028 (  _oid		 PGNSP PGUID -1 f b t \054 0	26 array_in array_out array_recv array_send - i x f 0 -1 0 _null_ _null_ ));
-#define OIDARRAYOID			1028
 DATA(insert OID = 1010 (  _tid		 PGNSP PGUID -1 f b t \054 0	27 array_in array_out array_recv array_send - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 1011 (  _xid		 PGNSP PGUID -1 f b t \054 0	28 array_in array_out array_recv array_send - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 1012 (  _cid		 PGNSP PGUID -1 f b t \054 0	29 array_in array_out array_recv array_send - i x f 0 -1 0 _null_ _null_ ));
@@ -517,6 +516,7 @@ DATA(insert OID = 2208 ( _regoper	   PGNSP PGUID -1 f b t \054 0 2203 array_in a
 DATA(insert OID = 2209 ( _regoperator  PGNSP PGUID -1 f b t \054 0 2204 array_in array_out array_recv array_send - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 2210 ( _regclass	   PGNSP PGUID -1 f b t \054 0 2205 array_in array_out array_recv array_send - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 2211 ( _regtype	   PGNSP PGUID -1 f b t \054 0 2206 array_in array_out array_recv array_send - i x f 0 -1 0 _null_ _null_ ));
+#define REGTYPEARRAYOID	2211
 
 /*
  * pseudo-types

src/test/regress/expected/prepare.out

@@ -149,18 +149,18 @@ PREPARE q7(unknown) AS
 SELECT name, statement, parameter_types FROM pg_prepared_statements
     ORDER BY name;
  name |                                                                                    statement                                                                                    |                    parameter_types                     
-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------
+------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------
  q2   | PREPARE q2(text) AS
 	SELECT datname, datistemplate, datallowconn
-	FROM pg_database WHERE datname = $1;                                                                          | {25}
+	FROM pg_database WHERE datname = $1;                                                                          | {text}
  q3   | PREPARE q3(text, int, float, boolean, oid, smallint) AS
 	SELECT * FROM tenk1 WHERE string4 = $1 AND (four = $2 OR
-	ten = $3::bigint OR true = $4 OR oid = $5 OR odd = $6::int); | {25,23,701,16,26,21}
+	ten = $3::bigint OR true = $4 OR oid = $5 OR odd = $6::int); | {text,integer,"double precision",boolean,oid,smallint}
  q5   | PREPARE q5(int, text) AS
-	SELECT * FROM tenk1 WHERE unique1 = $1 OR stringu1 = $2;                                                                                              | {23,25}
+	SELECT * FROM tenk1 WHERE unique1 = $1 OR stringu1 = $2;                                                                                              | {integer,text}
  q6   | PREPARE q6 AS
-    SELECT * FROM tenk1 WHERE unique1 = $1 AND stringu1 = $2;                                                                                                     | {23,19}
+    SELECT * FROM tenk1 WHERE unique1 = $1 AND stringu1 = $2;                                                                                                     | {integer,name}
  q7   | PREPARE q7(unknown) AS
-    SELECT * FROM road WHERE thepath = $1;                                                                                                               | {602}
+    SELECT * FROM road WHERE thepath = $1;                                                                                                               | {path}
 (5 rows)
 

src/test/regress/expected/rules.out

@@ -1280,7 +1280,7 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
  pg_group                 | SELECT pg_authid.rolname AS groname, pg_authid.oid AS grosysid, ARRAY(SELECT pg_auth_members.member FROM pg_auth_members WHERE (pg_auth_members.roleid = pg_authid.oid)) AS grolist FROM pg_authid WHERE (NOT pg_authid.rolcanlogin);
  pg_indexes               | SELECT n.nspname AS schemaname, c.relname AS tablename, i.relname AS indexname, t.spcname AS "tablespace", pg_get_indexdef(i.oid) AS indexdef FROM ((((pg_index x JOIN pg_class c ON ((c.oid = x.indrelid))) JOIN pg_class i ON ((i.oid = x.indexrelid))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) LEFT JOIN pg_tablespace t ON ((t.oid = i.reltablespace))) WHERE ((c.relkind = 'r'::"char") AND (i.relkind = 'i'::"char"));
  pg_locks                 | SELECT l.locktype, l."database", l.relation, l.page, l.tuple, l.transactionid, l.classid, l.objid, l.objsubid, l."transaction", l.pid, l."mode", l."granted" FROM pg_lock_status() l(locktype text, "database" oid, relation oid, page integer, tuple smallint, transactionid xid, classid oid, objid oid, objsubid smallint, "transaction" xid, pid integer, "mode" text, "granted" boolean);
- pg_prepared_statements   | SELECT p.name, p."statement", p.prepare_time, p.parameter_types, p.from_sql FROM pg_prepared_statement() p(name text, "statement" text, prepare_time timestamp with time zone, parameter_types oid[], from_sql boolean);
+ pg_prepared_statements   | SELECT p.name, p."statement", p.prepare_time, p.parameter_types, p.from_sql FROM pg_prepared_statement() p(name text, "statement" text, prepare_time timestamp with time zone, parameter_types regtype[], from_sql boolean);
  pg_prepared_xacts        | SELECT p."transaction", p.gid, p."prepared", u.rolname AS "owner", d.datname AS "database" FROM ((pg_prepared_xact() p("transaction" xid, gid text, "prepared" timestamp with time zone, ownerid oid, dbid oid) LEFT JOIN pg_authid u ON ((p.ownerid = u.oid))) LEFT JOIN pg_database d ON ((p.dbid = d.oid)));
  pg_roles                 | SELECT pg_authid.rolname, pg_authid.rolsuper, pg_authid.rolinherit, pg_authid.rolcreaterole, pg_authid.rolcreatedb, pg_authid.rolcatupdate, pg_authid.rolcanlogin, pg_authid.rolconnlimit, '********'::text AS rolpassword, pg_authid.rolvaliduntil, pg_authid.rolconfig, pg_authid.oid FROM pg_authid;
  pg_rules                 | SELECT n.nspname AS schemaname, c.relname AS tablename, r.rulename, pg_get_ruledef(r.oid) AS definition FROM ((pg_rewrite r JOIN pg_class c ON ((c.oid = r.ev_class))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (r.rulename <> '_RETURN'::name);