Re: export FUNC_MAX_ARGS as a read-only GUC variable

Tom Lane wrote:
> One could make a good case that INDEX_MAX_KEYS should be exported along
> with FUNC_MAX_ARGS, rather than letting people write client code that
> assumes they are the same.
> 
> I was intending to propose that we also export the following as
> read-only variables:
> 	* NAMEDATALEN
> 	* BLCKSZ
> 	* integer-vs-float datetime flag

OK, the attached includes the above -- result looks like:

regression=# select * from pg_settings where category like 'Compile%';
-[ RECORD 1 ]----------------------------------------------
name       | block_size
setting    | 8192
category   | Compiled-in Options
short_desc | Shows size of a disk block
extra_desc |
context    | internal
vartype    | integer
source     | default
min_val    | 8192
max_val    | 8192
-[ RECORD 2 ]----------------------------------------------
name       | func_max_args
setting    | 32
category   | Compiled-in Options
short_desc | Shows the maximum number of function arguments
extra_desc |
context    | internal
vartype    | integer
source     | default
min_val    | 32
max_val    | 32
-[ RECORD 3 ]----------------------------------------------
name       | index_max_keys
setting    | 32
category   | Compiled-in Options
short_desc | Shows the maximum number of index keys
extra_desc |
context    | internal
vartype    | integer
source     | default
min_val    | 32
max_val    | 32
-[ RECORD 4 ]----------------------------------------------
name       | integer_datetimes
setting    | on
category   | Compiled-in Options
short_desc | Datetimes are integer based
extra_desc |
context    | internal
vartype    | bool
source     | default
min_val    |
max_val    |
-[ RECORD 5 ]----------------------------------------------
name       | name_data_len
setting    | 63
category   | Compiled-in Options
short_desc | Shows the maximum identifier length
extra_desc |
context    | internal
vartype    | integer
source     | default
min_val    | 63
max_val    | 63


> If it's there it should be separate.  I think also there was some
> feeling it should be called "extra_desc" not "long_desc".

Done. Also added "category" which displays config_group_names[conf->group]


> Please set the GUC_NOT_IN_SAMPLE and GUC_DISALLOW_IN_FILE flag bits on
> each of these variables, too.  I know we are not using these flags for
> anything yet, but we should try to get them right...

Done.

I'll update the docs once I'm sure we're done iterating on these changes.

Any further comments?

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	1 Dec 2003 05:49:21 -0000
***************
*** 260,267 ****
  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 
      ON UPDATE TO pg_settings 
--- 260,267 ----
  CREATE VIEW pg_settings AS 
      SELECT * 
      FROM pg_show_all_settings() AS A 
!     (name text, setting text, category text, short_desc text, extra_desc text,
!      context text, vartype text, source text, min_val text, max_val text);
  
  CREATE RULE pg_settings_u AS 
      ON UPDATE TO pg_settings 
Index: src/backend/utils/misc/guc.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/utils/misc/guc.c,v
retrieving revision 1.173
diff -c -r1.173 guc.c
*** src/backend/utils/misc/guc.c	1 Dec 2003 03:55:21 -0000	1.173
--- src/backend/utils/misc/guc.c	1 Dec 2003 05:49:23 -0000
***************
*** 156,162 ****
  static char *session_authorization_string;
  static char *timezone_string;
  static char *XactIsoLevel_string;
! 
  
  /* Macros for freeing malloc'd pointers only if appropriate to do so */
  /* Some of these tests are probably redundant, but be safe ... */
--- 156,166 ----
  static char *session_authorization_string;
  static char *timezone_string;
  static char *XactIsoLevel_string;
! static int	func_max_args;
! static int	index_max_keys;
! static int	name_data_len;
! static int	block_size;
! static bool integer_datetimes;
  
  /* Macros for freeing malloc'd pointers only if appropriate to do so */
  /* Some of these tests are probably redundant, but be safe ... */
***************
*** 302,307 ****
--- 306,313 ----
  	gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
  	/* DEVELOPER_OPTIONS */
  	gettext_noop("Developer Options"),
+ 	/* COMPILE_OPTIONS */
+ 	gettext_noop("Compiled-in Options"),
  	/* help_config wants this array to be null-terminated */
  	NULL
  };
***************
*** 832,837 ****
--- 838,857 ----
  		true, NULL, NULL
  	},
  
+ 	{
+ 		{"integer_datetimes", PGC_INTERNAL, COMPILE_OPTIONS,
+ 			gettext_noop("Datetimes are integer based"),
+ 			NULL,
+ 			GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+ 		},
+ 		&integer_datetimes,
+ #ifdef HAVE_INT64_TIMESTAMP
+ 		true, NULL, NULL
+ #else
+ 		false, NULL, NULL
+ #endif
+ 	},
+ 
  	/* End-of-list marker */
  	{
  		{NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
***************
*** 1228,1233 ****
--- 1248,1293 ----
  		100, 1, 1000, NULL, NULL
  	},
  
+ 	{
+ 		{"func_max_args", PGC_INTERNAL, COMPILE_OPTIONS,
+ 			gettext_noop("Shows the maximum number of function arguments"),
+ 			NULL,
+ 			GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+ 		},
+ 		&func_max_args,
+ 		FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
+ 	},
+ 
+ 	{
+ 		{"index_max_keys", PGC_INTERNAL, COMPILE_OPTIONS,
+ 			gettext_noop("Shows the maximum number of index keys"),
+ 			NULL,
+ 			GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+ 		},
+ 		&index_max_keys,
+ 		INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS, NULL, NULL
+ 	},
+ 
+ 	{
+ 		{"name_data_len", PGC_INTERNAL, COMPILE_OPTIONS,
+ 			gettext_noop("Shows the maximum identifier length"),
+ 			NULL,
+ 			GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+ 		},
+ 		&name_data_len,
+ 		NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1, NULL, NULL
+ 	},
+ 
+ 	{
+ 		{"block_size", PGC_INTERNAL, COMPILE_OPTIONS,
+ 			gettext_noop("Shows size of a disk block"),
+ 			NULL,
+ 			GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+ 		},
+ 		&block_size,
+ 		BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
+ 	},
+ 
  	/* End-of-list marker */
  	{
  		{NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
***************
*** 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)
--- 3528,3550 ----
  	/* setting : use _ShowOption in order to avoid duplicating the logic */
  	values[1] = _ShowOption(conf);
  
+ 	/* group */
+ 	values[2] = config_group_names[conf->group];
+ 
+ 	/* short_desc */
+ 	values[3] = conf->short_desc;
+ 
+ 	/* extra_desc */
+ 	values[4] = conf->long_desc;
+ 
  	/* context */
! 	values[5] = GucContext_Names[conf->context];
  
  	/* vartype */
! 	values[6] = config_type_names[conf->vartype];
  
  	/* source */
! 	values[7] = 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;
  
--- 3552,3561 ----
  		case PGC_BOOL:
  			{
  				/* min_val */
! 				values[8] = NULL;
  
  				/* max_val */
! 				values[9] = 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;
  
--- 3565,3575 ----
  
  				/* min_val */
  				snprintf(buffer, sizeof(buffer), "%d", lconf->min);
! 				values[8] = pstrdup(buffer);
  
  				/* max_val */
  				snprintf(buffer, sizeof(buffer), "%d", lconf->max);
! 				values[9] = 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;
  
--- 3579,3599 ----
  
  				/* min_val */
  				snprintf(buffer, sizeof(buffer), "%g", lconf->min);
! 				values[8] = pstrdup(buffer);
  
  				/* max_val */
  				snprintf(buffer, sizeof(buffer), "%g", lconf->max);
! 				values[9] = pstrdup(buffer);
  			}
  			break;
  
  		case PGC_STRING:
  			{
  				/* min_val */
! 				values[8] = NULL;
  
  				/* max_val */
! 				values[9] = NULL;
  			}
  			break;
  
***************
*** 3536,3545 ****
  				 */
  
  				/* min_val */
! 				values[5] = NULL;
  
  				/* max_val */
! 				values[6] = NULL;
  			}
  			break;
  	}
--- 3605,3614 ----
  				 */
  
  				/* min_val */
! 				values[8] = NULL;
  
  				/* max_val */
! 				values[9] = 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)
--- 3651,3657 ----
   * show_all_settings - equiv to SHOW ALL command but implemented as
   * a Table Function.
   */
! #define NUM_PG_SETTINGS_ATTS	10
  
  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 */
--- 3685,3705 ----
  						   TEXTOID, -1, 0, false);
  		TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
  						   TEXTOID, -1, 0, false);
! 		TupleDescInitEntry(tupdesc, (AttrNumber) 3, "category",
! 						   TEXTOID, -1, 0, false);
! 		TupleDescInitEntry(tupdesc, (AttrNumber) 4, "short_desc",
! 						   TEXTOID, -1, 0, false);
! 		TupleDescInitEntry(tupdesc, (AttrNumber) 5, "extra_desc",
! 						   TEXTOID, -1, 0, false);
! 		TupleDescInitEntry(tupdesc, (AttrNumber) 6, "context",
  						   TEXTOID, -1, 0, false);
! 		TupleDescInitEntry(tupdesc, (AttrNumber) 7, "vartype",
  						   TEXTOID, -1, 0, false);
! 		TupleDescInitEntry(tupdesc, (AttrNumber) 8, "source",
  						   TEXTOID, -1, 0, false);
! 		TupleDescInitEntry(tupdesc, (AttrNumber) 9, "min_val",
  						   TEXTOID, -1, 0, false);
! 		TupleDescInitEntry(tupdesc, (AttrNumber) 10, "max_val",
  						   TEXTOID, -1, 0, false);
  
  		/* allocate a slot for a tuple with this tupdesc */
Index: src/include/utils/guc_tables.h
===================================================================
RCS file: /cvsroot/pgsql-server/src/include/utils/guc_tables.h,v
retrieving revision 1.7
diff -c -r1.7 guc_tables.h
*** src/include/utils/guc_tables.h	29 Nov 2003 22:41:15 -0000	1.7
--- src/include/utils/guc_tables.h	1 Dec 2003 05:49:23 -0000
***************
*** 50,56 ****
  	COMPAT_OPTIONS,
  	COMPAT_OPTIONS_PREVIOUS,
  	COMPAT_OPTIONS_CLIENT,
! 	DEVELOPER_OPTIONS
  };
  
  /*
--- 50,57 ----
  	COMPAT_OPTIONS,
  	COMPAT_OPTIONS_PREVIOUS,
  	COMPAT_OPTIONS_CLIENT,
! 	DEVELOPER_OPTIONS,
! 	COMPILE_OPTIONS
  };
  
  /*
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	1 Dec 2003 05:49:23 -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.category, a.short_desc, a.extra_desc, a.context, a.vartype, a.source, a.min_val, a.max_val FROM pg_show_all_settings() a(name text, setting text, category text, short_desc text, extra_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;