I was thinking of proposing that we provide something just about like that as a standard function (written in C, not in plpgsql, so that it would be available whether or not you'd installed plpgsql). There are some places in the information_schema that desperately need it --- right now, the value of FUNC_MAX_ARGS is effectively hard-wired into some of the information_schema views, which means they are broken if one changes that #define. We could fix this if we had a function like the above and exported FUNC_MAX_ARGS as a read-only GUC variable.
First installment. The attached exports FUNC_MAX_ARGS as a read-only GUC variable -- func_max_args. Comments?
While I was in guc.c, I also added short_desc to the definition of the pg_settings view. I wasn't sure if I ought to add the long_desc too, and if so, should it be it's own column in the view, or be concatenated with short_desc -- any thoughts on that?
Current output looks like this:
regression=# \x Expanded display is on. regression=# select * from pg_settings where name = 'func_max_args'; -[ RECORD 1 ]----------------------------------------------------------- name | func_max_args setting | 32 short_desc | Shows the compiled-in maximum number of function arguments. context | internal vartype | integer source | default min_val | 32 max_val | 32
This will require a catalog version bump when I apply it (not done in the attached patch).
Joe
Index: src/backend/catalog/system_views.sql
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/catalog/system_views.sql,v
retrieving revision 1.3
diff -c -r1.3 system_views.sql
*** src/backend/catalog/system_views.sql 29 Nov 2003 22:39:40 -0000 1.3
--- src/backend/catalog/system_views.sql 30 Nov 2003 04:58:51 -0000
***************
*** 260,266 ****
CREATE VIEW pg_settings AS
SELECT *
FROM pg_show_all_settings() AS A
! (name text, setting text, context text, vartype text,
source text, min_val text, max_val text);
CREATE RULE pg_settings_u AS
--- 260,266 ----
CREATE VIEW pg_settings AS
SELECT *
FROM pg_show_all_settings() AS A
! (name text, setting text, short_desc text, context text, vartype text,
source text, min_val text, max_val text);
CREATE RULE pg_settings_u AS
Index: src/backend/utils/misc/guc.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/utils/misc/guc.c,v
retrieving revision 1.172
diff -c -r1.172 guc.c
*** src/backend/utils/misc/guc.c 29 Nov 2003 19:52:03 -0000 1.172
--- src/backend/utils/misc/guc.c 30 Nov 2003 04:58:52 -0000
***************
*** 156,161 ****
--- 156,162 ----
static char *session_authorization_string;
static char *timezone_string;
static char *XactIsoLevel_string;
+ static int func_max_args;
/* Macros for freeing malloc'd pointers only if appropriate to do so */
***************
*** 862,867 ****
--- 863,878 ----
8, 1, INT_MAX, NULL, NULL
},
{
+ /* Can't be set in postgresql.conf */
+ {"func_max_args", PGC_INTERNAL, UNGROUPED,
+ gettext_noop("Shows the compiled-in maximum number of function
"
+ "arguments."),
+ NULL
+ },
+ &func_max_args,
+ FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
+ },
+ {
{"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
gettext_noop("Sets the FROM-list size beyond which JOIN
constructs are not "
"flattened."),
***************
*** 3468,3481 ****
/* setting : use _ShowOption in order to avoid duplicating the logic */
values[1] = _ShowOption(conf);
/* context */
! values[2] = GucContext_Names[conf->context];
/* vartype */
! values[3] = config_type_names[conf->vartype];
/* source */
! values[4] = GucSource_Names[conf->source];
/* now get the type specifc attributes */
switch (conf->vartype)
--- 3479,3495 ----
/* setting : use _ShowOption in order to avoid duplicating the logic */
values[1] = _ShowOption(conf);
+ /* short_desc */
+ values[2] = conf->short_desc;
+
/* context */
! values[3] = GucContext_Names[conf->context];
/* vartype */
! values[4] = config_type_names[conf->vartype];
/* source */
! values[5] = GucSource_Names[conf->source];
/* now get the type specifc attributes */
switch (conf->vartype)
***************
*** 3483,3492 ****
case PGC_BOOL:
{
/* min_val */
! values[5] = NULL;
/* max_val */
! values[6] = NULL;
}
break;
--- 3497,3506 ----
case PGC_BOOL:
{
/* min_val */
! values[6] = NULL;
/* max_val */
! values[7] = NULL;
}
break;
***************
*** 3496,3506 ****
/* min_val */
snprintf(buffer, sizeof(buffer), "%d", lconf->min);
! values[5] = pstrdup(buffer);
/* max_val */
snprintf(buffer, sizeof(buffer), "%d", lconf->max);
! values[6] = pstrdup(buffer);
}
break;
--- 3510,3520 ----
/* min_val */
snprintf(buffer, sizeof(buffer), "%d", lconf->min);
! values[6] = pstrdup(buffer);
/* max_val */
snprintf(buffer, sizeof(buffer), "%d", lconf->max);
! values[7] = pstrdup(buffer);
}
break;
***************
*** 3510,3530 ****
/* min_val */
snprintf(buffer, sizeof(buffer), "%g", lconf->min);
! values[5] = pstrdup(buffer);
/* max_val */
snprintf(buffer, sizeof(buffer), "%g", lconf->max);
! values[6] = pstrdup(buffer);
}
break;
case PGC_STRING:
{
/* min_val */
! values[5] = NULL;
/* max_val */
! values[6] = NULL;
}
break;
--- 3524,3544 ----
/* min_val */
snprintf(buffer, sizeof(buffer), "%g", lconf->min);
! values[6] = pstrdup(buffer);
/* max_val */
snprintf(buffer, sizeof(buffer), "%g", lconf->max);
! values[7] = pstrdup(buffer);
}
break;
case PGC_STRING:
{
/* min_val */
! values[6] = NULL;
/* max_val */
! values[7] = NULL;
}
break;
***************
*** 3536,3545 ****
*/
/* min_val */
! values[5] = NULL;
/* max_val */
! values[6] = NULL;
}
break;
}
--- 3550,3559 ----
*/
/* min_val */
! values[6] = NULL;
/* max_val */
! values[7] = NULL;
}
break;
}
***************
*** 3582,3588 ****
* show_all_settings - equiv to SHOW ALL command but implemented as
* a Table Function.
*/
! #define NUM_PG_SETTINGS_ATTS 7
Datum
show_all_settings(PG_FUNCTION_ARGS)
--- 3596,3602 ----
* show_all_settings - equiv to SHOW ALL command but implemented as
* a Table Function.
*/
! #define NUM_PG_SETTINGS_ATTS 8
Datum
show_all_settings(PG_FUNCTION_ARGS)
***************
*** 3616,3630 ****
TEXTOID, -1, 0, false);
TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 3, "context",
TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 4, "vartype",
TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 5, "source",
TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 6, "min_val",
TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 7, "max_val",
TEXTOID, -1, 0, false);
/* allocate a slot for a tuple with this tupdesc */
--- 3630,3646 ----
TEXTOID, -1, 0, false);
TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 3, "short_desc",
! TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 4, "context",
TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 5, "vartype",
TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 6, "source",
TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 7, "min_val",
TEXTOID, -1, 0, false);
! TupleDescInitEntry(tupdesc, (AttrNumber) 8, "max_val",
TEXTOID, -1, 0, false);
/* allocate a slot for a tuple with this tupdesc */
Index: src/test/regress/expected/rules.out
===================================================================
RCS file: /cvsroot/pgsql-server/src/test/regress/expected/rules.out,v
retrieving revision 1.82
diff -c -r1.82 rules.out
*** src/test/regress/expected/rules.out 21 Nov 2003 22:32:49 -0000 1.82
--- src/test/regress/expected/rules.out 30 Nov 2003 04:58:53 -0000
***************
*** 1278,1284 ****
pg_indexes | SELECT n.nspname AS schemaname, c.relname AS tablename,
i.relname AS indexname, 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))) WHERE ((c.relkind =
'r'::"char") AND (i.relkind = 'i'::"char"));
pg_locks | SELECT l.relation, l."database", l."transaction", l.pid,
l."mode", l.granted FROM pg_lock_status() l(relation oid, "database" oid,
"transaction" xid, pid integer, "mode" text, granted boolean);
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);
! pg_settings | SELECT a.name, a.setting, a.context, a.vartype,
a.source, a.min_val, a.max_val FROM pg_show_all_settings() a(name text, setting text,
context text, vartype text, source text, min_val text, max_val text);
pg_stat_activity | SELECT d.oid AS datid, d.datname,
pg_stat_get_backend_pid(s.backendid) AS procpid,
pg_stat_get_backend_userid(s.backendid) AS usesysid, u.usename,
pg_stat_get_backend_activity(s.backendid) AS current_query,
pg_stat_get_backend_activity_start(s.backendid) AS query_start FROM pg_database d,
(SELECT pg_stat_get_backend_idset() AS backendid) s, pg_shadow u WHERE
((pg_stat_get_backend_dbid(s.backendid) = d.oid) AND
(pg_stat_get_backend_userid(s.backendid) = u.usesysid));
pg_stat_all_indexes | SELECT c.oid AS relid, i.oid AS indexrelid, n.nspname AS
schemaname, c.relname, i.relname AS indexrelname, pg_stat_get_numscans(i.oid) AS
idx_scan, pg_stat_get_tuples_returned(i.oid) AS idx_tup_read,
pg_stat_get_tuples_fetched(i.oid) AS idx_tup_fetch FROM (((pg_class c JOIN pg_index x
ON ((c.oid = x.indrelid))) JOIN pg_class i ON ((i.oid = x.indexrelid))) LEFT JOIN
pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (c.relkind = 'r'::"char");
pg_stat_all_tables | SELECT c.oid AS relid, n.nspname AS schemaname,
c.relname, pg_stat_get_numscans(c.oid) AS seq_scan, pg_stat_get_tuples_returned(c.oid)
AS seq_tup_read, sum(pg_stat_get_numscans(i.indexrelid)) AS idx_scan,
sum(pg_stat_get_tuples_fetched(i.indexrelid)) AS idx_tup_fetch,
pg_stat_get_tuples_inserted(c.oid) AS n_tup_ins, pg_stat_get_tuples_updated(c.oid) AS
n_tup_upd, pg_stat_get_tuples_deleted(c.oid) AS n_tup_del FROM ((pg_class c LEFT JOIN
pg_index i ON ((c.oid = i.indrelid))) LEFT JOIN pg_namespace n ON ((n.oid =
c.relnamespace))) WHERE (c.relkind = 'r'::"char") GROUP BY c.oid, n.nspname, c.relname;
--- 1278,1284 ----
pg_indexes | SELECT n.nspname AS schemaname, c.relname AS tablename,
i.relname AS indexname, 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))) WHERE ((c.relkind =
'r'::"char") AND (i.relkind = 'i'::"char"));
pg_locks | SELECT l.relation, l."database", l."transaction", l.pid,
l."mode", l.granted FROM pg_lock_status() l(relation oid, "database" oid,
"transaction" xid, pid integer, "mode" text, granted boolean);
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);
! pg_settings | SELECT a.name, a.setting, a.short_desc, a.context,
a.vartype, a.source, a.min_val, a.max_val FROM pg_show_all_settings() a(name text,
setting text, short_desc text, context text, vartype text, source text, min_val text,
max_val text);
pg_stat_activity | SELECT d.oid AS datid, d.datname,
pg_stat_get_backend_pid(s.backendid) AS procpid,
pg_stat_get_backend_userid(s.backendid) AS usesysid, u.usename,
pg_stat_get_backend_activity(s.backendid) AS current_query,
pg_stat_get_backend_activity_start(s.backendid) AS query_start FROM pg_database d,
(SELECT pg_stat_get_backend_idset() AS backendid) s, pg_shadow u WHERE
((pg_stat_get_backend_dbid(s.backendid) = d.oid) AND
(pg_stat_get_backend_userid(s.backendid) = u.usesysid));
pg_stat_all_indexes | SELECT c.oid AS relid, i.oid AS indexrelid, n.nspname AS
schemaname, c.relname, i.relname AS indexrelname, pg_stat_get_numscans(i.oid) AS
idx_scan, pg_stat_get_tuples_returned(i.oid) AS idx_tup_read,
pg_stat_get_tuples_fetched(i.oid) AS idx_tup_fetch FROM (((pg_class c JOIN pg_index x
ON ((c.oid = x.indrelid))) JOIN pg_class i ON ((i.oid = x.indexrelid))) LEFT JOIN
pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (c.relkind = 'r'::"char");
pg_stat_all_tables | SELECT c.oid AS relid, n.nspname AS schemaname,
c.relname, pg_stat_get_numscans(c.oid) AS seq_scan, pg_stat_get_tuples_returned(c.oid)
AS seq_tup_read, sum(pg_stat_get_numscans(i.indexrelid)) AS idx_scan,
sum(pg_stat_get_tuples_fetched(i.indexrelid)) AS idx_tup_fetch,
pg_stat_get_tuples_inserted(c.oid) AS n_tup_ins, pg_stat_get_tuples_updated(c.oid) AS
n_tup_upd, pg_stat_get_tuples_deleted(c.oid) AS n_tup_del FROM ((pg_class c LEFT JOIN
pg_index i ON ((c.oid = i.indrelid))) LEFT JOIN pg_namespace n ON ((n.oid =
c.relnamespace))) WHERE (c.relkind = 'r'::"char") GROUP BY c.oid, n.nspname, c.relname;
---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
