Remove read-only server settings lc_collate and lc_ctype

The GUC settings lc_collate and lc_ctype are from a time when those
locale settings were cluster-global.  When those locale settings were
made per-database (PG 8.4), the settings were kept as read-only.  As
of PG 15, you can use ICU as the per-database locale provider, so
examining these settings is already less meaningful and possibly
confusing, since you need to look into pg_database to find out what is
really happening, and they would likely become fully obsolete in the
future anyway.

Reviewed-by: Jeff Davis <pgsql@j-davis.com>
Discussion: https://www.postgresql.org/message-id/696054d1-bc88-b6ab-129a-18b8bce6a6f0@enterprisedb.com

8 files changed, 16 insertions, 46 deletions

diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 6856ed99e7d..561bd13ed24 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -483,10 +483,6 @@ CheckMyDatabase(const char *name, bool am_superuser, bool override_allow_connect
 							 quote_identifier(name))));
 	}
 
-	/* Make the locale settings visible as GUC variables, too */
-	SetConfigOption("lc_collate", collate, PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
-	SetConfigOption("lc_ctype", ctype, PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
-
 	ReleaseSysCache(tup);
 }
 
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 68aecad66f4..4665b0a35c3 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -563,8 +563,6 @@ static char *syslog_ident_str;
 static double phony_random_seed;
 static char *client_encoding_string;
 static char *datestyle_string;
-static char *locale_collate;
-static char *locale_ctype;
 static char *server_encoding_string;
 static char *server_version_string;
 static int	server_version_num;
@@ -4050,30 +4048,6 @@ struct config_string ConfigureNamesString[] =
 		NULL, NULL, NULL
 	},
 
-	/* See main.c about why defaults for LC_foo are not all alike */
-
-	{
-		{"lc_collate", PGC_INTERNAL, PRESET_OPTIONS,
-			gettext_noop("Shows the collation order locale."),
-			NULL,
-			GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
-		},
-		&locale_collate,
-		"C",
-		NULL, NULL, NULL
-	},
-
-	{
-		{"lc_ctype", PGC_INTERNAL, PRESET_OPTIONS,
-			gettext_noop("Shows the character classification and case conversion locale."),
-			NULL,
-			GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
-		},
-		&locale_ctype,
-		"C",
-		NULL, NULL, NULL
-	},
-
 	{
 		{"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
 			gettext_noop("Sets the language in which messages are displayed."),
diff --git a/src/test/regress/expected/collate.icu.utf8.out b/src/test/regress/expected/collate.icu.utf8.out
index c658ee1404d..00dee24549a 100644
--- a/src/test/regress/expected/collate.icu.utf8.out
+++ b/src/test/regress/expected/collate.icu.utf8.out
@@ -1023,7 +1023,7 @@ SET client_min_messages TO WARNING;
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test0 (provider = icu, locale = ' ||
-          quote_literal(current_setting('lc_collate')) || ');';
+          quote_literal((SELECT daticulocale FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test0 FROM "C"; -- fail, duplicate name
@@ -1031,7 +1031,7 @@ ERROR:  collation "test0" already exists
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test1 (provider = icu, locale = ' ||
-          quote_literal(current_setting('lc_collate')) || ');';
+          quote_literal((SELECT daticulocale FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 RESET client_min_messages;
diff --git a/src/test/regress/expected/collate.linux.utf8.out b/src/test/regress/expected/collate.linux.utf8.out
index 6d34667cebc..01664f7c1b5 100644
--- a/src/test/regress/expected/collate.linux.utf8.out
+++ b/src/test/regress/expected/collate.linux.utf8.out
@@ -1027,7 +1027,7 @@ CREATE SCHEMA test_schema;
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test0 (locale = ' ||
-          quote_literal(current_setting('lc_collate')) || ');';
+          quote_literal((SELECT datcollate FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test0 FROM "C"; -- fail, duplicate name
@@ -1039,9 +1039,9 @@ NOTICE:  collation "test0" for encoding "UTF8" already exists, skipping
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test1 (lc_collate = ' ||
-          quote_literal(current_setting('lc_collate')) ||
+          quote_literal((SELECT datcollate FROM pg_database WHERE datname = current_database())) ||
           ', lc_ctype = ' ||
-          quote_literal(current_setting('lc_ctype')) || ');';
+          quote_literal((SELECT datctype FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test3 (lc_collate = 'en_US.utf8'); -- fail, need lc_ctype
diff --git a/src/test/regress/expected/collate.windows.win1252.out b/src/test/regress/expected/collate.windows.win1252.out
index 61b421161fa..b7b93959de9 100644
--- a/src/test/regress/expected/collate.windows.win1252.out
+++ b/src/test/regress/expected/collate.windows.win1252.out
@@ -863,7 +863,7 @@ CREATE SCHEMA test_schema;
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test0 (locale = ' ||
-          quote_literal(current_setting('lc_collate')) || ');';
+          quote_literal((SELECT datcollate FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test0 FROM "C"; -- fail, duplicate name
@@ -875,9 +875,9 @@ NOTICE:  collation "test0" for encoding "WIN1252" already exists, skipping
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test1 (lc_collate = ' ||
-          quote_literal(current_setting('lc_collate')) ||
+          quote_literal((SELECT datcollate FROM pg_database WHERE datname = current_database())) ||
           ', lc_ctype = ' ||
-          quote_literal(current_setting('lc_ctype')) || ');';
+          quote_literal((SELECT datctype FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test3 (lc_collate = 'en_US.utf8'); -- fail, need lc_ctype
diff --git a/src/test/regress/sql/collate.icu.utf8.sql b/src/test/regress/sql/collate.icu.utf8.sql
index 7bd09012810..a8001b4b8e9 100644
--- a/src/test/regress/sql/collate.icu.utf8.sql
+++ b/src/test/regress/sql/collate.icu.utf8.sql
@@ -362,14 +362,14 @@ SET client_min_messages TO WARNING;
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test0 (provider = icu, locale = ' ||
-          quote_literal(current_setting('lc_collate')) || ');';
+          quote_literal((SELECT daticulocale FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test0 FROM "C"; -- fail, duplicate name
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test1 (provider = icu, locale = ' ||
-          quote_literal(current_setting('lc_collate')) || ');';
+          quote_literal((SELECT daticulocale FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 
diff --git a/src/test/regress/sql/collate.linux.utf8.sql b/src/test/regress/sql/collate.linux.utf8.sql
index 2b787507c55..132d13af0a8 100644
--- a/src/test/regress/sql/collate.linux.utf8.sql
+++ b/src/test/regress/sql/collate.linux.utf8.sql
@@ -359,7 +359,7 @@ CREATE SCHEMA test_schema;
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test0 (locale = ' ||
-          quote_literal(current_setting('lc_collate')) || ');';
+          quote_literal((SELECT datcollate FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test0 FROM "C"; -- fail, duplicate name
@@ -368,9 +368,9 @@ CREATE COLLATION IF NOT EXISTS test0 (locale = 'foo'); -- ok, skipped
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test1 (lc_collate = ' ||
-          quote_literal(current_setting('lc_collate')) ||
+          quote_literal((SELECT datcollate FROM pg_database WHERE datname = current_database())) ||
           ', lc_ctype = ' ||
-          quote_literal(current_setting('lc_ctype')) || ');';
+          quote_literal((SELECT datctype FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test3 (lc_collate = 'en_US.utf8'); -- fail, need lc_ctype
diff --git a/src/test/regress/sql/collate.windows.win1252.sql b/src/test/regress/sql/collate.windows.win1252.sql
index b5c45e18103..353d769a5bd 100644
--- a/src/test/regress/sql/collate.windows.win1252.sql
+++ b/src/test/regress/sql/collate.windows.win1252.sql
@@ -310,7 +310,7 @@ CREATE SCHEMA test_schema;
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test0 (locale = ' ||
-          quote_literal(current_setting('lc_collate')) || ');';
+          quote_literal((SELECT datcollate FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test0 FROM "C"; -- fail, duplicate name
@@ -319,9 +319,9 @@ CREATE COLLATION IF NOT EXISTS test0 (locale = 'foo'); -- ok, skipped
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test1 (lc_collate = ' ||
-          quote_literal(current_setting('lc_collate')) ||
+          quote_literal((SELECT datcollate FROM pg_database WHERE datname = current_database())) ||
           ', lc_ctype = ' ||
-          quote_literal(current_setting('lc_ctype')) || ');';
+          quote_literal((SELECT datctype FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test3 (lc_collate = 'en_US.utf8'); -- fail, need lc_ctype