0001-Change-collate-and-ctype-fields-to-type-text.patch

From 1c46bf3138ad42074971aa3130142236de7e63f7 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Fri, 21 Jan 2022 10:01:25 +0100
Subject: [PATCH] Change collate and ctype fields to type text

This changes the data type of the catalog fields datcollate, datctype,
collcollate, and collctype from name to text.  There wasn't ever a
really good reason for them to be of type name; presumably this was
just carried over from when they were fixed-size fields in pg_control,
first into the corresponding pg_database fields, and then to
pg_collation.  The values are not identifiers or object names, and we
don't ever look them up that way.

Changing to type text saves space in the typical case, since locale
names are typically less than 10 bytes long.  But it is also possible
that an ICU locale name with several customization options appended
could be longer than 63 bytes, so this also enables that case, which
was previously probably broken.

Discussion: https://www.postgresql.org/message-id/flat/5e756dd6-0e91-d778-96fd-b1bcb06c161a@2ndquadrant.com
---
 doc/src/sgml/catalogs.sgml           | 40 +++++++++++++--------------
 src/backend/catalog/pg_collation.c   | 10 ++-----
 src/backend/commands/collationcmds.c | 41 +++++++++++++++++++---------
 src/backend/commands/dbcommands.c    | 21 ++++++++++----
 src/backend/utils/adt/pg_locale.c    | 29 +++++++++++++-------
 src/backend/utils/init/postinit.c    | 11 ++++++--
 src/include/catalog/pg_collation.h   |  4 +--
 src/include/catalog/pg_database.h    | 12 ++++----
 src/include/utils/pg_locale.h        |  2 ++
 9 files changed, 104 insertions(+), 66 deletions(-)

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 1e65c426b2..7d5b0b1656 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -2368,7 +2368,7 @@ <title><structname>pg_collation</structname> Columns</title>
 
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
-       <structfield>collcollate</structfield> <type>name</type>
+       <structfield>collcollate</structfield> <type>text</type>
       </para>
       <para>
        <symbol>LC_COLLATE</symbol> for this collation object
@@ -2377,7 +2377,7 @@ <title><structname>pg_collation</structname> Columns</title>
 
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
-       <structfield>collctype</structfield> <type>name</type>
+       <structfield>collctype</structfield> <type>text</type>
       </para>
       <para>
        <symbol>LC_CTYPE</symbol> for this collation object
@@ -2951,24 +2951,6 @@ <title><structname>pg_database</structname> Columns</title>
       </para></entry>
      </row>
 
-     <row>
-      <entry role="catalog_table_entry"><para role="column_definition">
-       <structfield>datcollate</structfield> <type>name</type>
-      </para>
-      <para>
-       LC_COLLATE for this database
-      </para></entry>
-     </row>
-
-     <row>
-      <entry role="catalog_table_entry"><para role="column_definition">
-       <structfield>datctype</structfield> <type>name</type>
-      </para>
-      <para>
-       LC_CTYPE for this database
-      </para></entry>
-     </row>
-
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>datistemplate</structfield> <type>bool</type>
@@ -3043,6 +3025,24 @@ <title><structname>pg_database</structname> Columns</title>
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>datcollate</structfield> <type>text</type>
+      </para>
+      <para>
+       LC_COLLATE for this database
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>datctype</structfield> <type>text</type>
+      </para>
+      <para>
+       LC_CTYPE for this database
+      </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>datacl</structfield> <type>aclitem[]</type>
diff --git a/src/backend/catalog/pg_collation.c b/src/backend/catalog/pg_collation.c
index 5be6600652..bfc02d3038 100644
--- a/src/backend/catalog/pg_collation.c
+++ b/src/backend/catalog/pg_collation.c
@@ -58,9 +58,7 @@ CollationCreate(const char *collname, Oid collnamespace,
 	HeapTuple	tup;
 	Datum		values[Natts_pg_collation];
 	bool		nulls[Natts_pg_collation];
-	NameData	name_name,
-				name_collate,
-				name_ctype;
+	NameData	name_name;
 	Oid			oid;
 	ObjectAddress myself,
 				referenced;
@@ -163,10 +161,8 @@ CollationCreate(const char *collname, Oid collnamespace,
 	values[Anum_pg_collation_collprovider - 1] = CharGetDatum(collprovider);
 	values[Anum_pg_collation_collisdeterministic - 1] = BoolGetDatum(collisdeterministic);
 	values[Anum_pg_collation_collencoding - 1] = Int32GetDatum(collencoding);
-	namestrcpy(&name_collate, collcollate);
-	values[Anum_pg_collation_collcollate - 1] = NameGetDatum(&name_collate);
-	namestrcpy(&name_ctype, collctype);
-	values[Anum_pg_collation_collctype - 1] = NameGetDatum(&name_ctype);
+	values[Anum_pg_collation_collcollate - 1] = CStringGetTextDatum(collcollate);
+	values[Anum_pg_collation_collctype - 1] = CStringGetTextDatum(collctype);
 	if (collversion)
 		values[Anum_pg_collation_collversion - 1] = CStringGetTextDatum(collversion);
 	else
diff --git a/src/backend/commands/collationcmds.c b/src/backend/commands/collationcmds.c
index 56748551de..12fc2316f9 100644
--- a/src/backend/commands/collationcmds.c
+++ b/src/backend/commands/collationcmds.c
@@ -129,18 +129,30 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 	{
 		Oid			collid;
 		HeapTuple	tp;
+		Datum		datum;
+		bool		isnull;
 
 		collid = get_collation_oid(defGetQualifiedName(fromEl), false);
 		tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid));
 		if (!HeapTupleIsValid(tp))
 			elog(ERROR, "cache lookup failed for collation %u", collid);
 
-		collcollate = pstrdup(NameStr(((Form_pg_collation) GETSTRUCT(tp))->collcollate));
-		collctype = pstrdup(NameStr(((Form_pg_collation) GETSTRUCT(tp))->collctype));
 		collprovider = ((Form_pg_collation) GETSTRUCT(tp))->collprovider;
 		collisdeterministic = ((Form_pg_collation) GETSTRUCT(tp))->collisdeterministic;
 		collencoding = ((Form_pg_collation) GETSTRUCT(tp))->collencoding;
 
+		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collcollate, &isnull);
+		if (!isnull)
+			collcollate = TextDatumGetCString(datum);
+		else
+			collcollate = NULL;
+
+		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collctype, &isnull);
+		if (!isnull)
+			collctype = TextDatumGetCString(datum);
+		else
+			collctype = NULL;
+
 		ReleaseSysCache(tp);
 
 		/*
@@ -314,7 +326,7 @@ AlterCollation(AlterCollationStmt *stmt)
 	Oid			collOid;
 	HeapTuple	tup;
 	Form_pg_collation collForm;
-	Datum		collversion;
+	Datum		datum;
 	bool		isnull;
 	char	   *oldversion;
 	char	   *newversion;
@@ -332,11 +344,12 @@ AlterCollation(AlterCollationStmt *stmt)
 		elog(ERROR, "cache lookup failed for collation %u", collOid);
 
 	collForm = (Form_pg_collation) GETSTRUCT(tup);
-	collversion = SysCacheGetAttr(COLLOID, tup, Anum_pg_collation_collversion,
-								  &isnull);
-	oldversion = isnull ? NULL : TextDatumGetCString(collversion);
+	datum = SysCacheGetAttr(COLLOID, tup, Anum_pg_collation_collversion, &isnull);
+	oldversion = isnull ? NULL : TextDatumGetCString(datum);
 
-	newversion = get_collation_actual_version(collForm->collprovider, NameStr(collForm->collcollate));
+	datum = SysCacheGetAttr(COLLOID, tup, Anum_pg_collation_collcollate, &isnull);
+	Assert(!isnull);
+	newversion = get_collation_actual_version(collForm->collprovider, TextDatumGetCString(datum));
 
 	/* cannot change from NULL to non-NULL or vice versa */
 	if ((!oldversion && newversion) || (oldversion && !newversion))
@@ -383,8 +396,9 @@ pg_collation_actual_version(PG_FUNCTION_ARGS)
 {
 	Oid			collid = PG_GETARG_OID(0);
 	HeapTuple	tp;
-	char	   *collcollate;
 	char		collprovider;
+	Datum		datum;
+	bool		isnull;
 	char	   *version;
 
 	tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid));
@@ -393,12 +407,13 @@ pg_collation_actual_version(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_UNDEFINED_OBJECT),
 				 errmsg("collation with OID %u does not exist", collid)));
 
-	collcollate = pstrdup(NameStr(((Form_pg_collation) GETSTRUCT(tp))->collcollate));
 	collprovider = ((Form_pg_collation) GETSTRUCT(tp))->collprovider;
 
-	ReleaseSysCache(tp);
+	datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collcollate, &isnull);
+	Assert(!isnull);
+	version = get_collation_actual_version(collprovider, TextDatumGetCString(datum));
 
-	version = get_collation_actual_version(collprovider, collcollate);
+	ReleaseSysCache(tp);
 
 	if (version)
 		PG_RETURN_TEXT_P(cstring_to_text(version));
@@ -546,7 +561,7 @@ pg_import_system_collations(PG_FUNCTION_ARGS)
 #ifdef READ_LOCALE_A_OUTPUT
 	{
 		FILE	   *locale_a_handle;
-		char		localebuf[NAMEDATALEN]; /* we assume ASCII so this is fine */
+		char		localebuf[LOCALE_NAME_BUFLEN];
 		int			nvalid = 0;
 		Oid			collid;
 		CollAliasData *aliases;
@@ -570,7 +585,7 @@ pg_import_system_collations(PG_FUNCTION_ARGS)
 		{
 			size_t		len;
 			int			enc;
-			char		alias[NAMEDATALEN];
+			char		alias[LOCALE_NAME_BUFLEN];
 
 			len = strlen(localebuf);
 
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index da8345561d..65b420aea6 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -523,10 +523,8 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 		DirectFunctionCall1(namein, CStringGetDatum(dbname));
 	new_record[Anum_pg_database_datdba - 1] = ObjectIdGetDatum(datdba);
 	new_record[Anum_pg_database_encoding - 1] = Int32GetDatum(encoding);
-	new_record[Anum_pg_database_datcollate - 1] =
-		DirectFunctionCall1(namein, CStringGetDatum(dbcollate));
-	new_record[Anum_pg_database_datctype - 1] =
-		DirectFunctionCall1(namein, CStringGetDatum(dbctype));
+	new_record[Anum_pg_database_datcollate - 1] = CStringGetTextDatum(dbcollate);
+	new_record[Anum_pg_database_datctype - 1] = CStringGetTextDatum(dbctype);
 	new_record[Anum_pg_database_datistemplate - 1] = BoolGetDatum(dbistemplate);
 	new_record[Anum_pg_database_datallowconn - 1] = BoolGetDatum(dballowconnections);
 	new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(dbconnlimit);
@@ -1820,6 +1818,9 @@ get_db_info(const char *name, LOCKMODE lockmode,
 
 			if (strcmp(name, NameStr(dbform->datname)) == 0)
 			{
+				Datum		datum;
+				bool		isnull;
+
 				/* oid of the database */
 				if (dbIdP)
 					*dbIdP = dbOid;
@@ -1846,9 +1847,17 @@ get_db_info(const char *name, LOCKMODE lockmode,
 					*dbTablespace = dbform->dattablespace;
 				/* default locale settings for this database */
 				if (dbCollate)
-					*dbCollate = pstrdup(NameStr(dbform->datcollate));
+				{
+					datum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_datcollate, &isnull);
+					Assert(!isnull);
+					*dbCollate = TextDatumGetCString(datum);
+				}
 				if (dbCtype)
-					*dbCtype = pstrdup(NameStr(dbform->datctype));
+				{
+					datum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_datctype, &isnull);
+					Assert(!isnull);
+					*dbCtype = TextDatumGetCString(datum);
+				}
 				ReleaseSysCache(tuple);
 				result = true;
 				break;
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 33cccc5c6c..aefa0818d0 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -179,7 +179,7 @@ pg_perm_setlocale(int category, const char *locale)
 	 */
 	if (category == LC_CTYPE)
 	{
-		static char save_lc_ctype[NAMEDATALEN + 20];
+		static char save_lc_ctype[LOCALE_NAME_BUFLEN];
 
 		/* copy setlocale() return value before callee invokes it again */
 		strlcpy(save_lc_ctype, result, sizeof(save_lc_ctype));
@@ -1288,17 +1288,21 @@ lookup_collation_cache(Oid collation, bool set_flags)
 	{
 		/* Attempt to set the flags */
 		HeapTuple	tp;
-		Form_pg_collation collform;
+		Datum		datum;
+		bool		isnull;
 		const char *collcollate;
 		const char *collctype;
 
 		tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collation));
 		if (!HeapTupleIsValid(tp))
 			elog(ERROR, "cache lookup failed for collation %u", collation);
-		collform = (Form_pg_collation) GETSTRUCT(tp);
 
-		collcollate = NameStr(collform->collcollate);
-		collctype = NameStr(collform->collctype);
+		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collcollate, &isnull);
+		Assert(!isnull);
+		collcollate = TextDatumGetCString(datum);
+		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collctype, &isnull);
+		Assert(!isnull);
+		collctype = TextDatumGetCString(datum);
 
 		cache_entry->collate_is_c = ((strcmp(collcollate, "C") == 0) ||
 									 (strcmp(collcollate, "POSIX") == 0));
@@ -1484,7 +1488,7 @@ pg_newlocale_from_collation(Oid collid)
 		const char *collctype pg_attribute_unused();
 		struct pg_locale_struct result;
 		pg_locale_t resultp;
-		Datum		collversion;
+		Datum		datum;
 		bool		isnull;
 
 		tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid));
@@ -1492,8 +1496,12 @@ pg_newlocale_from_collation(Oid collid)
 			elog(ERROR, "cache lookup failed for collation %u", collid);
 		collform = (Form_pg_collation) GETSTRUCT(tp);
 
-		collcollate = NameStr(collform->collcollate);
-		collctype = NameStr(collform->collctype);
+		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collcollate, &isnull);
+		Assert(!isnull);
+		collcollate = TextDatumGetCString(datum);
+		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collctype, &isnull);
+		Assert(!isnull);
+		collctype = TextDatumGetCString(datum);
 
 		/* We'll fill in the result struct locally before allocating memory */
 		memset(&result, 0, sizeof(result));
@@ -1587,13 +1595,15 @@ pg_newlocale_from_collation(Oid collid)
 #endif							/* not USE_ICU */
 		}
 
-		collversion = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collversion,
+		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collversion,
 									  &isnull);
 		if (!isnull)
 		{
 			char	   *actual_versionstr;
 			char	   *collversionstr;
 
+			collversionstr = TextDatumGetCString(datum);
+
 			actual_versionstr = get_collation_actual_version(collform->collprovider, collcollate);
 			if (!actual_versionstr)
 			{
@@ -1606,7 +1616,6 @@ pg_newlocale_from_collation(Oid collid)
 						(errmsg("collation \"%s\" has no actual version, but a version was specified",
 								NameStr(collform->collname))));
 			}
-			collversionstr = TextDatumGetCString(collversion);
 
 			if (strcmp(actual_versionstr, collversionstr) != 0)
 				ereport(WARNING,
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 0236165f60..d046caabd7 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -53,6 +53,7 @@
 #include "storage/sync.h"
 #include "tcop/tcopprot.h"
 #include "utils/acl.h"
+#include "utils/builtins.h"
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
 #include "utils/memutils.h"
@@ -306,6 +307,8 @@ CheckMyDatabase(const char *name, bool am_superuser, bool override_allow_connect
 {
 	HeapTuple	tup;
 	Form_pg_database dbform;
+	Datum		datum;
+	bool		isnull;
 	char	   *collate;
 	char	   *ctype;
 
@@ -389,8 +392,12 @@ CheckMyDatabase(const char *name, bool am_superuser, bool override_allow_connect
 					PGC_BACKEND, PGC_S_DYNAMIC_DEFAULT);
 
 	/* assign locale variables */
-	collate = NameStr(dbform->datcollate);
-	ctype = NameStr(dbform->datctype);
+	datum = SysCacheGetAttr(DATABASEOID, tup, Anum_pg_database_datcollate, &isnull);
+	Assert(!isnull);
+	collate = TextDatumGetCString(datum);
+	datum = SysCacheGetAttr(DATABASEOID, tup, Anum_pg_database_datctype, &isnull);
+	Assert(!isnull);
+	ctype = TextDatumGetCString(datum);
 
 	if (pg_perm_setlocale(LC_COLLATE, collate) == NULL)
 		ereport(FATAL,
diff --git a/src/include/catalog/pg_collation.h b/src/include/catalog/pg_collation.h
index bc746537c1..8763dd4080 100644
--- a/src/include/catalog/pg_collation.h
+++ b/src/include/catalog/pg_collation.h
@@ -39,9 +39,9 @@ CATALOG(pg_collation,3456,CollationRelationId)
 	char		collprovider;	/* see constants below */
 	bool		collisdeterministic BKI_DEFAULT(t);
 	int32		collencoding;	/* encoding for this collation; -1 = "all" */
-	NameData	collcollate;	/* LC_COLLATE setting */
-	NameData	collctype;		/* LC_CTYPE setting */
 #ifdef CATALOG_VARLEN			/* variable-length fields start here */
+	text		collcollate BKI_FORCE_NOT_NULL;		/* LC_COLLATE setting */
+	text		collctype BKI_FORCE_NOT_NULL;		/* LC_CTYPE setting */
 	text		collversion BKI_DEFAULT(_null_);	/* provider-dependent
 													 * version of collation
 													 * data */
diff --git a/src/include/catalog/pg_database.h b/src/include/catalog/pg_database.h
index 1ff6d3e50c..90b43a4ecc 100644
--- a/src/include/catalog/pg_database.h
+++ b/src/include/catalog/pg_database.h
@@ -40,12 +40,6 @@ CATALOG(pg_database,1262,DatabaseRelationId) BKI_SHARED_RELATION BKI_ROWTYPE_OID
 	/* character encoding */
 	int32		encoding;
 
-	/* LC_COLLATE setting */
-	NameData	datcollate;
-
-	/* LC_CTYPE setting */
-	NameData	datctype;
-
 	/* allowed as CREATE DATABASE template? */
 	bool		datistemplate;
 
@@ -65,6 +59,12 @@ CATALOG(pg_database,1262,DatabaseRelationId) BKI_SHARED_RELATION BKI_ROWTYPE_OID
 	Oid			dattablespace BKI_LOOKUP(pg_tablespace);
 
 #ifdef CATALOG_VARLEN			/* variable-length fields start here */
+	/* LC_COLLATE setting */
+	text		datcollate BKI_FORCE_NOT_NULL;
+
+	/* LC_CTYPE setting */
+	text		datctype BKI_FORCE_NOT_NULL;
+
 	/* access permissions */
 	aclitem		datacl[1];
 #endif
diff --git a/src/include/utils/pg_locale.h b/src/include/utils/pg_locale.h
index b4a2765983..30e423af0e 100644
--- a/src/include/utils/pg_locale.h
+++ b/src/include/utils/pg_locale.h
@@ -34,6 +34,8 @@
 #endif
 #endif
 
+/* use for libc locale names */
+#define LOCALE_NAME_BUFLEN 128
 
 /* GUC settings */
 extern char *locale_messages;
-- 
2.34.1