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 only a few 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.

Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/5e756dd6-0e91-d778-96fd-b1bcb06c161a@2ndquadrant.com

doc/src/sgml/catalogs.sgml

@@ -2368,7 +2368,7 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
 
      <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 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
 
      <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 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
       </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 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
       </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>

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,
+	NameData	name_name;
-				name_collate,
-				name_ctype;
 	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] = CStringGetTextDatum(collcollate);
-	values[Anum_pg_collation_collcollate - 1] = NameGetDatum(&name_collate);
+	values[Anum_pg_collation_collctype - 1] = CStringGetTextDatum(collctype);
-	namestrcpy(&name_ctype, collctype);
-	values[Anum_pg_collation_collctype - 1] = NameGetDatum(&name_ctype);
 	if (collversion)
 		values[Anum_pg_collation_collversion - 1] = CStringGetTextDatum(collversion);
 	else

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,
+	datum = SysCacheGetAttr(COLLOID, tup, Anum_pg_collation_collversion, &isnull);
-								  &isnull);
+	oldversion = isnull ? NULL : TextDatumGetCString(datum);
-	oldversion = isnull ? NULL : TextDatumGetCString(collversion);
 
-	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);
 

src/backend/commands/dbcommands.c

@@ -570,10 +570,8 @@ 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] =
+	new_record[Anum_pg_database_datcollate - 1] = CStringGetTextDatum(dbcollate);
-		DirectFunctionCall1(namein, CStringGetDatum(dbcollate));
+	new_record[Anum_pg_database_datctype - 1] = CStringGetTextDatum(dbctype);
-	new_record[Anum_pg_database_datctype - 1] =
-		DirectFunctionCall1(namein, CStringGetDatum(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);
@@ -1867,6 +1865,9 @@ 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;
@@ -1893,9 +1894,17 @@ 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;

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);
+		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collcollate, &isnull);
-		collctype = NameStr(collform->collctype);
+		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);
+		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collcollate, &isnull);
-		collctype = NameStr(collform->collctype);
+		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,

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);
+	datum = SysCacheGetAttr(DATABASEOID, tup, Anum_pg_database_datcollate, &isnull);
-	ctype = NameStr(dbform->datctype);
+	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,

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202201201
+#define CATALOG_VERSION_NO	202201271
 
 #endif

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 */

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

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;