v16-0004-Catalog-changes-preparing-for-builtin-collation-.patch

From 3456ed4e8639371a06ab9539d6e1e34762caa297 Mon Sep 17 00:00:00 2001
From: Jeff Davis <jeff@j-davis.com>
Date: Tue, 26 Dec 2023 13:32:48 -0800
Subject: [PATCH v16 4/5] Catalog changes preparing for builtin collation
 provider.

daticulocale -> datlocale, colliculocale -> colllocale.
---
 doc/src/sgml/bki.sgml                         |  2 +-
 doc/src/sgml/catalogs.sgml                    |  8 +-
 src/backend/catalog/pg_collation.c            | 10 +--
 src/backend/commands/collationcmds.c          | 34 +++----
 src/backend/commands/dbcommands.c             | 68 +++++++-------
 src/backend/utils/adt/pg_locale.c             |  4 +-
 src/backend/utils/init/postinit.c             |  2 +-
 src/bin/initdb/initdb.c                       | 41 ++++-----
 src/bin/initdb/t/001_initdb.pl                |  4 +-
 src/bin/pg_dump/pg_dump.c                     | 90 +++++++++++--------
 src/bin/pg_upgrade/info.c                     | 31 ++++---
 src/bin/pg_upgrade/pg_upgrade.c               | 34 ++++---
 src/bin/pg_upgrade/pg_upgrade.h               |  2 +-
 src/bin/pg_upgrade/t/002_pg_upgrade.pl        | 15 +++-
 src/bin/psql/describe.c                       | 20 +++--
 src/include/catalog/pg_collation.dat          |  2 +-
 src/include/catalog/pg_collation.h            |  4 +-
 src/include/catalog/pg_database.dat           |  2 +-
 src/include/catalog/pg_database.h             |  2 +-
 .../regress/expected/collate.icu.utf8.out     |  4 +-
 src/test/regress/expected/psql.out            | 18 ++--
 src/test/regress/sql/collate.icu.utf8.sql     |  4 +-
 22 files changed, 227 insertions(+), 174 deletions(-)

diff --git a/doc/src/sgml/bki.sgml b/doc/src/sgml/bki.sgml
index 315ba81951..3cd5bee7ff 100644
--- a/doc/src/sgml/bki.sgml
+++ b/doc/src/sgml/bki.sgml
@@ -186,7 +186,7 @@
   datlocprovider => 'LOCALE_PROVIDER', datistemplate => 't',
   datallowconn => 't', dathasloginevt => 'f', datconnlimit => '-1', datfrozenxid => '0',
   datminmxid => '1', dattablespace => 'pg_default', datcollate => 'LC_COLLATE',
-  datctype => 'LC_CTYPE', daticulocale => 'ICU_LOCALE', datacl => '_null_' },
+  datctype => 'LC_CTYPE', datlocale => 'DATLOCALE', datacl => '_null_' },
 
 ]
 ]]></programlisting>
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 3ec7391ec5..26d16d25c8 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -2422,10 +2422,10 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
 
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
-       <structfield>colliculocale</structfield> <type>text</type>
+       <structfield>colllocale</structfield> <type>text</type>
       </para>
       <para>
-       ICU locale ID for this collation object
+       Locale name for builtin or ICU provider
       </para></entry>
      </row>
 
@@ -3121,10 +3121,10 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
 
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
-       <structfield>daticulocale</structfield> <type>text</type>
+       <structfield>datlocale</structfield> <type>text</type>
       </para>
       <para>
-       ICU locale ID for this database
+       Locale name for builtin or ICU provider
       </para></entry>
      </row>
 
diff --git a/src/backend/catalog/pg_collation.c b/src/backend/catalog/pg_collation.c
index 5c8ccb8b3b..7bad94f908 100644
--- a/src/backend/catalog/pg_collation.c
+++ b/src/backend/catalog/pg_collation.c
@@ -49,7 +49,7 @@ CollationCreate(const char *collname, Oid collnamespace,
 				bool collisdeterministic,
 				int32 collencoding,
 				const char *collcollate, const char *collctype,
-				const char *colliculocale,
+				const char *colllocale,
 				const char *collicurules,
 				const char *collversion,
 				bool if_not_exists,
@@ -68,7 +68,7 @@ CollationCreate(const char *collname, Oid collnamespace,
 	Assert(collname);
 	Assert(collnamespace);
 	Assert(collowner);
-	Assert((collcollate && collctype) || colliculocale);
+	Assert((collcollate && collctype) || colllocale);
 
 	/*
 	 * Make sure there is no existing collation of same name & encoding.
@@ -191,10 +191,10 @@ CollationCreate(const char *collname, Oid collnamespace,
 		values[Anum_pg_collation_collctype - 1] = CStringGetTextDatum(collctype);
 	else
 		nulls[Anum_pg_collation_collctype - 1] = true;
-	if (colliculocale)
-		values[Anum_pg_collation_colliculocale - 1] = CStringGetTextDatum(colliculocale);
+	if (colllocale)
+		values[Anum_pg_collation_colllocale - 1] = CStringGetTextDatum(colllocale);
 	else
-		nulls[Anum_pg_collation_colliculocale - 1] = true;
+		nulls[Anum_pg_collation_colllocale - 1] = true;
 	if (collicurules)
 		values[Anum_pg_collation_collicurules - 1] = CStringGetTextDatum(collicurules);
 	else
diff --git a/src/backend/commands/collationcmds.c b/src/backend/commands/collationcmds.c
index 58c059fdb7..27564e569a 100644
--- a/src/backend/commands/collationcmds.c
+++ b/src/backend/commands/collationcmds.c
@@ -68,7 +68,7 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 	DefElem    *versionEl = NULL;
 	char	   *collcollate;
 	char	   *collctype;
-	char	   *colliculocale;
+	char	   *colllocale;
 	char	   *collicurules;
 	bool		collisdeterministic;
 	int			collencoding;
@@ -159,11 +159,11 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 		else
 			collctype = NULL;
 
-		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_colliculocale, &isnull);
+		datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_colllocale, &isnull);
 		if (!isnull)
-			colliculocale = TextDatumGetCString(datum);
+			colllocale = TextDatumGetCString(datum);
 		else
-			colliculocale = NULL;
+			colllocale = NULL;
 
 		/*
 		 * When the ICU locale comes from an existing collation, do not
@@ -196,7 +196,7 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 
 		collcollate = NULL;
 		collctype = NULL;
-		colliculocale = NULL;
+		colllocale = NULL;
 		collicurules = NULL;
 
 		if (providerEl)
@@ -236,7 +236,7 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 				collctype = defGetString(localeEl);
 			}
 			else
-				colliculocale = defGetString(localeEl);
+				colllocale = defGetString(localeEl);
 		}
 
 		if (lccollateEl)
@@ -261,7 +261,7 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 		}
 		else if (collprovider == COLLPROVIDER_ICU)
 		{
-			if (!colliculocale)
+			if (!colllocale)
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 						 errmsg("parameter \"%s\" must be specified",
@@ -273,20 +273,20 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 			 */
 			if (!IsBinaryUpgrade)
 			{
-				char	   *langtag = icu_language_tag(colliculocale,
+				char	   *langtag = icu_language_tag(colllocale,
 													   icu_validation_level);
 
-				if (langtag && strcmp(colliculocale, langtag) != 0)
+				if (langtag && strcmp(colllocale, langtag) != 0)
 				{
 					ereport(NOTICE,
 							(errmsg("using standard form \"%s\" for ICU locale \"%s\"",
-									langtag, colliculocale)));
+									langtag, colllocale)));
 
-					colliculocale = langtag;
+					colllocale = langtag;
 				}
 			}
 
-			icu_validate_locale(colliculocale);
+			icu_validate_locale(colllocale);
 		}
 
 		/*
@@ -334,7 +334,7 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 	}
 
 	if (!collversion)
-		collversion = get_collation_actual_version(collprovider, collprovider == COLLPROVIDER_ICU ? colliculocale : collcollate);
+		collversion = get_collation_actual_version(collprovider, collprovider == COLLPROVIDER_ICU ? colllocale : collcollate);
 
 	newoid = CollationCreate(collName,
 							 collNamespace,
@@ -344,7 +344,7 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 							 collencoding,
 							 collcollate,
 							 collctype,
-							 colliculocale,
+							 colllocale,
 							 collicurules,
 							 collversion,
 							 if_not_exists,
@@ -435,7 +435,7 @@ AlterCollation(AlterCollationStmt *stmt)
 	datum = SysCacheGetAttr(COLLOID, tup, Anum_pg_collation_collversion, &isnull);
 	oldversion = isnull ? NULL : TextDatumGetCString(datum);
 
-	datum = SysCacheGetAttrNotNull(COLLOID, tup, collForm->collprovider == COLLPROVIDER_ICU ? Anum_pg_collation_colliculocale : Anum_pg_collation_collcollate);
+	datum = SysCacheGetAttrNotNull(COLLOID, tup, collForm->collprovider == COLLPROVIDER_ICU ? Anum_pg_collation_colllocale : Anum_pg_collation_collcollate);
 	newversion = get_collation_actual_version(collForm->collprovider, TextDatumGetCString(datum));
 
 	/* cannot change from NULL to non-NULL or vice versa */
@@ -502,7 +502,7 @@ pg_collation_actual_version(PG_FUNCTION_ARGS)
 
 		datum = SysCacheGetAttrNotNull(DATABASEOID, dbtup,
 									   provider == COLLPROVIDER_ICU ?
-									   Anum_pg_database_daticulocale : Anum_pg_database_datcollate);
+									   Anum_pg_database_datlocale : Anum_pg_database_datcollate);
 
 		locale = TextDatumGetCString(datum);
 
@@ -523,7 +523,7 @@ pg_collation_actual_version(PG_FUNCTION_ARGS)
 		Assert(provider != COLLPROVIDER_DEFAULT);
 		datum = SysCacheGetAttrNotNull(COLLOID, colltp,
 									   provider == COLLPROVIDER_ICU ?
-									   Anum_pg_collation_colliculocale : Anum_pg_collation_collcollate);
+									   Anum_pg_collation_colllocale : Anum_pg_collation_collcollate);
 
 		locale = TextDatumGetCString(datum);
 
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 0a97a11314..8d327243b3 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -118,7 +118,7 @@ static bool get_db_info(const char *name, LOCKMODE lockmode,
 						Oid *dbIdP, Oid *ownerIdP,
 						int *encodingP, bool *dbIsTemplateP, bool *dbAllowConnP, bool *dbHasLoginEvtP,
 						TransactionId *dbFrozenXidP, MultiXactId *dbMinMultiP,
-						Oid *dbTablespace, char **dbCollate, char **dbCtype, char **dbIculocale,
+						Oid *dbTablespace, char **dbCollate, char **dbCtype, char **dbLocale,
 						char **dbIcurules,
 						char *dbLocProvider,
 						char **dbCollversion);
@@ -675,7 +675,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	int			src_encoding = -1;
 	char	   *src_collate = NULL;
 	char	   *src_ctype = NULL;
-	char	   *src_iculocale = NULL;
+	char	   *src_locale = NULL;
 	char	   *src_icurules = NULL;
 	char		src_locprovider = '\0';
 	char	   *src_collversion = NULL;
@@ -713,7 +713,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	const char *dbtemplate = NULL;
 	char	   *dbcollate = NULL;
 	char	   *dbctype = NULL;
-	char	   *dbiculocale = NULL;
+	char	   *dblocale = NULL;
 	char	   *dbicurules = NULL;
 	char		dblocprovider = '\0';
 	char	   *canonname;
@@ -903,7 +903,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	if (dctype && dctype->arg)
 		dbctype = defGetString(dctype);
 	if (diculocale && diculocale->arg)
-		dbiculocale = defGetString(diculocale);
+		dblocale = defGetString(diculocale);
 	if (dicurules && dicurules->arg)
 		dbicurules = defGetString(dicurules);
 	if (dlocprovider && dlocprovider->arg)
@@ -971,7 +971,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 					 &src_dboid, &src_owner, &src_encoding,
 					 &src_istemplate, &src_allowconn, &src_hasloginevt,
 					 &src_frozenxid, &src_minmxid, &src_deftablespace,
-					 &src_collate, &src_ctype, &src_iculocale, &src_icurules, &src_locprovider,
+					 &src_collate, &src_ctype, &src_locale, &src_icurules, &src_locprovider,
 					 &src_collversion))
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_DATABASE),
@@ -1027,12 +1027,12 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 		dbctype = src_ctype;
 	if (dblocprovider == '\0')
 		dblocprovider = src_locprovider;
-	if (dbiculocale == NULL && dblocprovider == COLLPROVIDER_ICU)
+	if (dblocale == NULL && dblocprovider == COLLPROVIDER_ICU)
 	{
 		if (dlocale && dlocale->arg)
-			dbiculocale = defGetString(dlocale);
+			dblocale = defGetString(dlocale);
 		else
-			dbiculocale = src_iculocale;
+			dblocale = src_locale;
 	}
 	if (dbicurules == NULL && dblocprovider == COLLPROVIDER_ICU)
 		dbicurules = src_icurules;
@@ -1071,7 +1071,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 		 * This would happen if template0 uses the libc provider but the new
 		 * database uses icu.
 		 */
-		if (!dbiculocale)
+		if (!dblocale)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("LOCALE or ICU_LOCALE must be specified")));
@@ -1081,26 +1081,26 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 		 * database, preserve locale string. Otherwise, canonicalize to a
 		 * language tag.
 		 */
-		if (!IsBinaryUpgrade && dbiculocale != src_iculocale)
+		if (!IsBinaryUpgrade && dblocale != src_locale)
 		{
-			char	   *langtag = icu_language_tag(dbiculocale,
+			char	   *langtag = icu_language_tag(dblocale,
 												   icu_validation_level);
 
-			if (langtag && strcmp(dbiculocale, langtag) != 0)
+			if (langtag && strcmp(dblocale, langtag) != 0)
 			{
 				ereport(NOTICE,
 						(errmsg("using standard form \"%s\" for ICU locale \"%s\"",
-								langtag, dbiculocale)));
+								langtag, dblocale)));
 
-				dbiculocale = langtag;
+				dblocale = langtag;
 			}
 		}
 
-		icu_validate_locale(dbiculocale);
+		icu_validate_locale(dblocale);
 	}
 	else
 	{
-		if (dbiculocale)
+		if (dblocale)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 					 errmsg("ICU locale cannot be specified unless locale provider is ICU")));
@@ -1157,13 +1157,13 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 			char	   *val1;
 			char	   *val2;
 
-			Assert(dbiculocale);
-			Assert(src_iculocale);
-			if (strcmp(dbiculocale, src_iculocale) != 0)
+			Assert(dblocale);
+			Assert(src_locale);
+			if (strcmp(dblocale, src_locale) != 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 						 errmsg("new ICU locale (%s) is incompatible with the ICU locale of the template database (%s)",
-								dbiculocale, src_iculocale),
+								dblocale, src_locale),
 						 errhint("Use the same ICU locale as in the template database, or use template0 as template.")));
 
 			val1 = dbicurules;
@@ -1197,7 +1197,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	{
 		char	   *actual_versionstr;
 
-		actual_versionstr = get_collation_actual_version(dblocprovider, dblocprovider == COLLPROVIDER_ICU ? dbiculocale : dbcollate);
+		actual_versionstr = get_collation_actual_version(dblocprovider, dblocprovider == COLLPROVIDER_ICU ? dblocale : dbcollate);
 		if (!actual_versionstr)
 			ereport(ERROR,
 					(errmsg("template database \"%s\" has a collation version, but no actual collation version could be determined",
@@ -1225,7 +1225,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	 * collation version, which is normally only the case for template0.
 	 */
 	if (dbcollversion == NULL)
-		dbcollversion = get_collation_actual_version(dblocprovider, dblocprovider == COLLPROVIDER_ICU ? dbiculocale : dbcollate);
+		dbcollversion = get_collation_actual_version(dblocprovider, dblocprovider == COLLPROVIDER_ICU ? dblocale : dbcollate);
 
 	/* Resolve default tablespace for new database */
 	if (dtablespacename && dtablespacename->arg)
@@ -1364,8 +1364,8 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	 * block on the unique index, and fail after we commit).
 	 */
 
-	Assert((dblocprovider == COLLPROVIDER_ICU && dbiculocale) ||
-		   (dblocprovider != COLLPROVIDER_ICU && !dbiculocale));
+	Assert((dblocprovider == COLLPROVIDER_ICU && dblocale) ||
+		   (dblocprovider != COLLPROVIDER_ICU && !dblocale));
 
 	/* Form tuple */
 	new_record[Anum_pg_database_oid - 1] = ObjectIdGetDatum(dboid);
@@ -1383,10 +1383,10 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	new_record[Anum_pg_database_dattablespace - 1] = ObjectIdGetDatum(dst_deftablespace);
 	new_record[Anum_pg_database_datcollate - 1] = CStringGetTextDatum(dbcollate);
 	new_record[Anum_pg_database_datctype - 1] = CStringGetTextDatum(dbctype);
-	if (dbiculocale)
-		new_record[Anum_pg_database_daticulocale - 1] = CStringGetTextDatum(dbiculocale);
+	if (dblocale)
+		new_record[Anum_pg_database_datlocale - 1] = CStringGetTextDatum(dblocale);
 	else
-		new_record_nulls[Anum_pg_database_daticulocale - 1] = true;
+		new_record_nulls[Anum_pg_database_datlocale - 1] = true;
 	if (dbicurules)
 		new_record[Anum_pg_database_daticurules - 1] = CStringGetTextDatum(dbicurules);
 	else
@@ -2472,7 +2472,7 @@ AlterDatabaseRefreshColl(AlterDatabaseRefreshCollStmt *stmt)
 	datum = heap_getattr(tuple, Anum_pg_database_datcollversion, RelationGetDescr(rel), &isnull);
 	oldversion = isnull ? NULL : TextDatumGetCString(datum);
 
-	datum = heap_getattr(tuple, datForm->datlocprovider == COLLPROVIDER_ICU ? Anum_pg_database_daticulocale : Anum_pg_database_datcollate, RelationGetDescr(rel), &isnull);
+	datum = heap_getattr(tuple, datForm->datlocprovider == COLLPROVIDER_ICU ? Anum_pg_database_datlocale : Anum_pg_database_datcollate, RelationGetDescr(rel), &isnull);
 	if (isnull)
 		elog(ERROR, "unexpected null in pg_database");
 	newversion = get_collation_actual_version(datForm->datlocprovider, TextDatumGetCString(datum));
@@ -2670,7 +2670,7 @@ pg_database_collation_actual_version(PG_FUNCTION_ARGS)
 
 	datlocprovider = ((Form_pg_database) GETSTRUCT(tp))->datlocprovider;
 
-	datum = SysCacheGetAttrNotNull(DATABASEOID, tp, datlocprovider == COLLPROVIDER_ICU ? Anum_pg_database_daticulocale : Anum_pg_database_datcollate);
+	datum = SysCacheGetAttrNotNull(DATABASEOID, tp, datlocprovider == COLLPROVIDER_ICU ? Anum_pg_database_datlocale : Anum_pg_database_datcollate);
 	version = get_collation_actual_version(datlocprovider, TextDatumGetCString(datum));
 
 	ReleaseSysCache(tp);
@@ -2697,7 +2697,7 @@ get_db_info(const char *name, LOCKMODE lockmode,
 			Oid *dbIdP, Oid *ownerIdP,
 			int *encodingP, bool *dbIsTemplateP, bool *dbAllowConnP, bool *dbHasLoginEvtP,
 			TransactionId *dbFrozenXidP, MultiXactId *dbMinMultiP,
-			Oid *dbTablespace, char **dbCollate, char **dbCtype, char **dbIculocale,
+			Oid *dbTablespace, char **dbCollate, char **dbCtype, char **dbLocale,
 			char **dbIcurules,
 			char *dbLocProvider,
 			char **dbCollversion)
@@ -2808,13 +2808,13 @@ get_db_info(const char *name, LOCKMODE lockmode,
 					datum = SysCacheGetAttrNotNull(DATABASEOID, tuple, Anum_pg_database_datctype);
 					*dbCtype = TextDatumGetCString(datum);
 				}
-				if (dbIculocale)
+				if (dbLocale)
 				{
-					datum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_daticulocale, &isnull);
+					datum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_datlocale, &isnull);
 					if (isnull)
-						*dbIculocale = NULL;
+						*dbLocale = NULL;
 					else
-						*dbIculocale = TextDatumGetCString(datum);
+						*dbLocale = TextDatumGetCString(datum);
 				}
 				if (dbIcurules)
 				{
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 79b59b0af7..45fe847320 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -1606,7 +1606,7 @@ pg_newlocale_from_collation(Oid collid)
 			const char *iculocstr;
 			const char *icurules;
 
-			datum = SysCacheGetAttrNotNull(COLLOID, tp, Anum_pg_collation_colliculocale);
+			datum = SysCacheGetAttrNotNull(COLLOID, tp, Anum_pg_collation_colllocale);
 			iculocstr = TextDatumGetCString(datum);
 
 			datum = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collicurules, &isnull);
@@ -1627,7 +1627,7 @@ pg_newlocale_from_collation(Oid collid)
 
 			collversionstr = TextDatumGetCString(datum);
 
-			datum = SysCacheGetAttrNotNull(COLLOID, tp, collform->collprovider == COLLPROVIDER_ICU ? Anum_pg_collation_colliculocale : Anum_pg_collation_collcollate);
+			datum = SysCacheGetAttrNotNull(COLLOID, tp, collform->collprovider == COLLPROVIDER_ICU ? Anum_pg_collation_colllocale : Anum_pg_collation_collcollate);
 
 			actual_versionstr = get_collation_actual_version(collform->collprovider,
 															 TextDatumGetCString(datum));
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 1ad3367159..6dbee5556a 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -427,7 +427,7 @@ CheckMyDatabase(const char *name, bool am_superuser, bool override_allow_connect
 	{
 		char	   *icurules;
 
-		datum = SysCacheGetAttrNotNull(DATABASEOID, tup, Anum_pg_database_daticulocale);
+		datum = SysCacheGetAttrNotNull(DATABASEOID, tup, Anum_pg_database_datlocale);
 		iculocale = TextDatumGetCString(datum);
 
 		datum = SysCacheGetAttr(DATABASEOID, tup, Anum_pg_database_daticurules, &isnull);
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index ac409b0006..8f4b456995 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -145,7 +145,8 @@ static char *lc_numeric = NULL;
 static char *lc_time = NULL;
 static char *lc_messages = NULL;
 static char locale_provider = COLLPROVIDER_LIBC;
-static char *icu_locale = NULL;
+static char *datlocale = NULL;
+static bool icu_locale_specified = false;
 static char *icu_rules = NULL;
 static const char *default_text_search_config = NULL;
 static char *username = NULL;
@@ -1515,8 +1516,8 @@ bootstrap_template1(void)
 	bki_lines = replace_token(bki_lines, "LC_CTYPE",
 							  escape_quotes_bki(lc_ctype));
 
-	bki_lines = replace_token(bki_lines, "ICU_LOCALE",
-							  icu_locale ? escape_quotes_bki(icu_locale) : "_null_");
+	bki_lines = replace_token(bki_lines, "DATLOCALE",
+							  datlocale ? escape_quotes_bki(datlocale) : "_null_");
 
 	bki_lines = replace_token(bki_lines, "ICU_RULES",
 							  icu_rules ? escape_quotes_bki(icu_rules) : "_null_");
@@ -2363,8 +2364,8 @@ setlocales(void)
 			lc_monetary = locale;
 		if (!lc_messages)
 			lc_messages = locale;
-		if (!icu_locale && locale_provider == COLLPROVIDER_ICU)
-			icu_locale = locale;
+		if (!datlocale && locale_provider != COLLPROVIDER_LIBC)
+			datlocale = locale;
 	}
 
 	/*
@@ -2390,22 +2391,21 @@ setlocales(void)
 	lc_messages = canonname;
 #endif
 
+	if (locale_provider != COLLPROVIDER_LIBC && datlocale == NULL)
+		pg_fatal("locale must be specified unless provider is libc");
+
 	if (locale_provider == COLLPROVIDER_ICU)
 	{
 		char	   *langtag;
 
-		/* acquire default locale from the environment, if not specified */
-		if (icu_locale == NULL)
-			pg_fatal("ICU locale must be specified");
-
 		/* canonicalize to a language tag */
-		langtag = icu_language_tag(icu_locale);
+		langtag = icu_language_tag(datlocale);
 		printf(_("Using language tag \"%s\" for ICU locale \"%s\".\n"),
-			   langtag, icu_locale);
-		pg_free(icu_locale);
-		icu_locale = langtag;
+			   langtag, datlocale);
+		pg_free(datlocale);
+		datlocale = langtag;
 
-		icu_validate_locale(icu_locale);
+		icu_validate_locale(datlocale);
 
 		/*
 		 * In supported builds, the ICU locale ID will be opened during
@@ -2599,14 +2599,14 @@ setup_locale_encoding(void)
 		strcmp(lc_ctype, lc_numeric) == 0 &&
 		strcmp(lc_ctype, lc_monetary) == 0 &&
 		strcmp(lc_ctype, lc_messages) == 0 &&
-		(!icu_locale || strcmp(lc_ctype, icu_locale) == 0))
+		(!datlocale || strcmp(lc_ctype, datlocale) == 0))
 		printf(_("The database cluster will be initialized with locale \"%s\".\n"), lc_ctype);
 	else
 	{
 		printf(_("The database cluster will be initialized with this locale configuration:\n"));
-		printf(_("  provider:    %s\n"), collprovider_name(locale_provider));
-		if (icu_locale)
-			printf(_("  ICU locale:  %s\n"), icu_locale);
+		printf(_("  default collation provider:  %s\n"), collprovider_name(locale_provider));
+		if (locale_provider != COLLPROVIDER_LIBC)
+			printf(_("  default collation locale:    %s\n"), datlocale);
 		printf(_("  LC_COLLATE:  %s\n"
 				 "  LC_CTYPE:    %s\n"
 				 "  LC_MESSAGES: %s\n"
@@ -3277,7 +3277,8 @@ main(int argc, char *argv[])
 					pg_fatal("unrecognized locale provider: %s", optarg);
 				break;
 			case 16:
-				icu_locale = pg_strdup(optarg);
+				datlocale = pg_strdup(optarg);
+				icu_locale_specified = true;
 				break;
 			case 17:
 				icu_rules = pg_strdup(optarg);
@@ -3312,7 +3313,7 @@ main(int argc, char *argv[])
 		exit(1);
 	}
 
-	if (icu_locale && locale_provider != COLLPROVIDER_ICU)
+	if (icu_locale_specified && locale_provider != COLLPROVIDER_ICU)
 		pg_fatal("%s cannot be specified unless locale provider \"%s\" is chosen",
 				 "--icu-locale", "icu");
 
diff --git a/src/bin/initdb/t/001_initdb.pl b/src/bin/initdb/t/001_initdb.pl
index 03376cc0f7..eb17c0e8f9 100644
--- a/src/bin/initdb/t/001_initdb.pl
+++ b/src/bin/initdb/t/001_initdb.pl
@@ -117,7 +117,7 @@ if ($ENV{with_icu} eq 'yes')
 {
 	command_fails_like(
 		[ 'initdb', '--no-sync', '--locale-provider=icu', "$tempdir/data2" ],
-		qr/initdb: error: ICU locale must be specified/,
+		qr/initdb: error: locale must be specified unless provider is libc/,
 		'locale provider ICU requires --icu-locale');
 
 	command_ok(
@@ -138,7 +138,7 @@ if ($ENV{with_icu} eq 'yes')
 			'--lc-monetary=C', '--lc-time=C',
 			"$tempdir/data4"
 		],
-		qr/^\s+ICU locale:\s+und\n/ms,
+		qr/^\s+default collation locale:\s+und\n/ms,
 		'options --locale-provider=icu --locale=und --lc-*=C');
 
 	command_fails_like(
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 22d1e6cf92..939ab62ff9 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -2982,7 +2982,7 @@ dumpDatabase(Archive *fout)
 				i_datlocprovider,
 				i_collate,
 				i_ctype,
-				i_daticulocale,
+				i_datlocale,
 				i_daticurules,
 				i_frozenxid,
 				i_minmxid,
@@ -3001,7 +3001,7 @@ dumpDatabase(Archive *fout)
 			   *datlocprovider,
 			   *collate,
 			   *ctype,
-			   *iculocale,
+			   *locale,
 			   *icurules,
 			   *datistemplate,
 			   *datconnlimit,
@@ -3025,10 +3025,12 @@ dumpDatabase(Archive *fout)
 		appendPQExpBufferStr(dbQry, "datminmxid, ");
 	else
 		appendPQExpBufferStr(dbQry, "0 AS datminmxid, ");
-	if (fout->remoteVersion >= 150000)
-		appendPQExpBufferStr(dbQry, "datlocprovider, daticulocale, datcollversion, ");
+	if (fout->remoteVersion >= 170000)
+		appendPQExpBufferStr(dbQry, "datlocprovider, datlocale, datcollversion, ");
+	else if (fout->remoteVersion >= 150000)
+		appendPQExpBufferStr(dbQry, "datlocprovider, daticulocale AS datlocale, datcollversion, ");
 	else
-		appendPQExpBufferStr(dbQry, "'c' AS datlocprovider, NULL AS daticulocale, NULL AS datcollversion, ");
+		appendPQExpBufferStr(dbQry, "'c' AS datlocprovider, NULL AS datlocale, NULL AS datcollversion, ");
 	if (fout->remoteVersion >= 160000)
 		appendPQExpBufferStr(dbQry, "daticurules, ");
 	else
@@ -3049,7 +3051,7 @@ dumpDatabase(Archive *fout)
 	i_datlocprovider = PQfnumber(res, "datlocprovider");
 	i_collate = PQfnumber(res, "datcollate");
 	i_ctype = PQfnumber(res, "datctype");
-	i_daticulocale = PQfnumber(res, "daticulocale");
+	i_datlocale = PQfnumber(res, "datlocale");
 	i_daticurules = PQfnumber(res, "daticurules");
 	i_frozenxid = PQfnumber(res, "datfrozenxid");
 	i_minmxid = PQfnumber(res, "datminmxid");
@@ -3068,10 +3070,10 @@ dumpDatabase(Archive *fout)
 	datlocprovider = PQgetvalue(res, 0, i_datlocprovider);
 	collate = PQgetvalue(res, 0, i_collate);
 	ctype = PQgetvalue(res, 0, i_ctype);
-	if (!PQgetisnull(res, 0, i_daticulocale))
-		iculocale = PQgetvalue(res, 0, i_daticulocale);
+	if (!PQgetisnull(res, 0, i_datlocale))
+		locale = PQgetvalue(res, 0, i_datlocale);
 	else
-		iculocale = NULL;
+		locale = NULL;
 	if (!PQgetisnull(res, 0, i_daticurules))
 		icurules = PQgetvalue(res, 0, i_daticurules);
 	else
@@ -3118,29 +3120,36 @@ dumpDatabase(Archive *fout)
 		pg_fatal("unrecognized locale provider: %s",
 				 datlocprovider);
 
-	if (strlen(collate) > 0 && strcmp(collate, ctype) == 0)
+	if (!locale && datlocprovider[0] != 'c')
+		pg_log_warning("database '%s' with provider '%s' missing datlocale",
+					   datname, datlocprovider);
+
+	if (locale && datlocprovider[0] == 'c')
+		pg_log_warning("database '%s' with provider 'c' has non-NULL locale '%s'",
+					   datname, locale);
+
+	/* if collate and ctype are equal, and locale is NULL, use LOCALE */
+	if (!locale && strlen(collate) > 0 && strcmp(collate, ctype) == 0)
+		locale = collate;
+
+	/* output LC_COLLATE and LC_CTYPE if different from LOCALE */
+	if (strlen(collate) > 0 && (!locale || strcmp(collate, locale) != 0))
 	{
-		appendPQExpBufferStr(creaQry, " LOCALE = ");
+		appendPQExpBufferStr(creaQry, " LC_COLLATE = ");
 		appendStringLiteralAH(creaQry, collate, fout);
 	}
-	else
+	if (strlen(ctype) > 0 && (!locale || strcmp(ctype, locale) != 0))
 	{
-		if (strlen(collate) > 0)
-		{
-			appendPQExpBufferStr(creaQry, " LC_COLLATE = ");
-			appendStringLiteralAH(creaQry, collate, fout);
-		}
-		if (strlen(ctype) > 0)
-		{
-			appendPQExpBufferStr(creaQry, " LC_CTYPE = ");
-			appendStringLiteralAH(creaQry, ctype, fout);
-		}
+		appendPQExpBufferStr(creaQry, " LC_CTYPE = ");
+		appendStringLiteralAH(creaQry, ctype, fout);
 	}
-	if (iculocale)
+
+	if (locale)
 	{
-		appendPQExpBufferStr(creaQry, " ICU_LOCALE = ");
-		appendStringLiteralAH(creaQry, iculocale, fout);
+		appendPQExpBufferStr(creaQry, " LOCALE = ");
+		appendStringLiteralAH(creaQry, locale, fout);
 	}
+
 	if (icurules)
 	{
 		appendPQExpBufferStr(creaQry, " ICU_RULES = ");
@@ -13798,12 +13807,12 @@ dumpCollation(Archive *fout, const CollInfo *collinfo)
 	int			i_collisdeterministic;
 	int			i_collcollate;
 	int			i_collctype;
-	int			i_colliculocale;
+	int			i_colllocale;
 	int			i_collicurules;
 	const char *collprovider;
 	const char *collcollate;
 	const char *collctype;
-	const char *colliculocale;
+	const char *colllocale;
 	const char *collicurules;
 
 	/* Do nothing in data-only dump */
@@ -13835,12 +13844,15 @@ dumpCollation(Archive *fout, const CollInfo *collinfo)
 		appendPQExpBufferStr(query,
 							 "true AS collisdeterministic, ");
 
-	if (fout->remoteVersion >= 150000)
+	if (fout->remoteVersion >= 170000)
+		appendPQExpBufferStr(query,
+							 "colllocale, ");
+	else if (fout->remoteVersion >= 150000)
 		appendPQExpBufferStr(query,
-							 "colliculocale, ");
+							 "colliculocale AS colllocale, ");
 	else
 		appendPQExpBufferStr(query,
-							 "NULL AS colliculocale, ");
+							 "NULL AS colllocale, ");
 
 	if (fout->remoteVersion >= 160000)
 		appendPQExpBufferStr(query,
@@ -13862,7 +13874,7 @@ dumpCollation(Archive *fout, const CollInfo *collinfo)
 	i_collisdeterministic = PQfnumber(res, "collisdeterministic");
 	i_collcollate = PQfnumber(res, "collcollate");
 	i_collctype = PQfnumber(res, "collctype");
-	i_colliculocale = PQfnumber(res, "colliculocale");
+	i_colllocale = PQfnumber(res, "colllocale");
 	i_collicurules = PQfnumber(res, "collicurules");
 
 	collprovider = PQgetvalue(res, 0, i_collprovider);
@@ -13889,10 +13901,10 @@ dumpCollation(Archive *fout, const CollInfo *collinfo)
 			collctype = NULL;
 	}
 
-	if (!PQgetisnull(res, 0, i_colliculocale))
-		colliculocale = PQgetvalue(res, 0, i_colliculocale);
+	if (!PQgetisnull(res, 0, i_colllocale))
+		colllocale = PQgetvalue(res, 0, i_colllocale);
 	else
-		colliculocale = NULL;
+		colllocale = NULL;
 
 	if (!PQgetisnull(res, 0, i_collicurules))
 		collicurules = PQgetvalue(res, 0, i_collicurules);
@@ -13922,7 +13934,7 @@ dumpCollation(Archive *fout, const CollInfo *collinfo)
 
 	if (collprovider[0] == 'd')
 	{
-		if (collcollate || collctype || colliculocale || collicurules)
+		if (collcollate || collctype || colllocale || collicurules)
 			pg_log_warning("invalid collation \"%s\"", qcollname);
 
 		/* no locale -- the default collation cannot be reloaded anyway */
@@ -13931,16 +13943,16 @@ dumpCollation(Archive *fout, const CollInfo *collinfo)
 	{
 		if (fout->remoteVersion >= 150000)
 		{
-			if (collcollate || collctype || !colliculocale)
+			if (collcollate || collctype || !colllocale)
 				pg_log_warning("invalid collation \"%s\"", qcollname);
 
 			appendPQExpBufferStr(q, ", locale = ");
-			appendStringLiteralAH(q, colliculocale ? colliculocale : "",
+			appendStringLiteralAH(q, colllocale ? colllocale : "",
 								  fout);
 		}
 		else
 		{
-			if (!collcollate || !collctype || colliculocale ||
+			if (!collcollate || !collctype || colllocale ||
 				strcmp(collcollate, collctype) != 0)
 				pg_log_warning("invalid collation \"%s\"", qcollname);
 
@@ -13956,7 +13968,7 @@ dumpCollation(Archive *fout, const CollInfo *collinfo)
 	}
 	else if (collprovider[0] == 'c')
 	{
-		if (colliculocale || collicurules || !collcollate || !collctype)
+		if (colllocale || collicurules || !collcollate || !collctype)
 			pg_log_warning("invalid collation \"%s\"", qcollname);
 
 		if (collcollate && collctype && strcmp(collcollate, collctype) == 0)
diff --git a/src/bin/pg_upgrade/info.c b/src/bin/pg_upgrade/info.c
index 74e02b3f82..0a6e763b71 100644
--- a/src/bin/pg_upgrade/info.c
+++ b/src/bin/pg_upgrade/info.c
@@ -328,18 +328,24 @@ get_template0_info(ClusterInfo *cluster)
 	int			i_datlocprovider;
 	int			i_datcollate;
 	int			i_datctype;
-	int			i_daticulocale;
+	int			i_datlocale;
 
-	if (GET_MAJOR_VERSION(cluster->major_version) >= 1500)
+	if (GET_MAJOR_VERSION(cluster->major_version) >= 1700)
 		dbres = executeQueryOrDie(conn,
 								  "SELECT encoding, datlocprovider, "
-								  "       datcollate, datctype, daticulocale "
+								  "       datcollate, datctype, datlocale "
+								  "FROM	pg_catalog.pg_database "
+								  "WHERE datname='template0'");
+	else if (GET_MAJOR_VERSION(cluster->major_version) >= 1500)
+		dbres = executeQueryOrDie(conn,
+								  "SELECT encoding, datlocprovider, "
+								  "       datcollate, datctype, daticulocale AS datlocale"
 								  "FROM	pg_catalog.pg_database "
 								  "WHERE datname='template0'");
 	else
 		dbres = executeQueryOrDie(conn,
 								  "SELECT encoding, 'c' AS datlocprovider, "
-								  "       datcollate, datctype, NULL AS daticulocale "
+								  "       datcollate, datctype, NULL AS datlocale "
 								  "FROM	pg_catalog.pg_database "
 								  "WHERE datname='template0'");
 
@@ -353,16 +359,16 @@ get_template0_info(ClusterInfo *cluster)
 	i_datlocprovider = PQfnumber(dbres, "datlocprovider");
 	i_datcollate = PQfnumber(dbres, "datcollate");
 	i_datctype = PQfnumber(dbres, "datctype");
-	i_daticulocale = PQfnumber(dbres, "daticulocale");
+	i_datlocale = PQfnumber(dbres, "datlocale");
 
 	locale->db_encoding = atoi(PQgetvalue(dbres, 0, i_datencoding));
 	locale->db_collprovider = PQgetvalue(dbres, 0, i_datlocprovider)[0];
 	locale->db_collate = pg_strdup(PQgetvalue(dbres, 0, i_datcollate));
 	locale->db_ctype = pg_strdup(PQgetvalue(dbres, 0, i_datctype));
-	if (PQgetisnull(dbres, 0, i_daticulocale))
-		locale->db_iculocale = NULL;
+	if (PQgetisnull(dbres, 0, i_datlocale))
+		locale->db_locale = NULL;
 	else
-		locale->db_iculocale = pg_strdup(PQgetvalue(dbres, 0, i_daticulocale));
+		locale->db_locale = pg_strdup(PQgetvalue(dbres, 0, i_datlocale));
 
 	cluster->template0 = locale;
 
@@ -392,12 +398,15 @@ get_db_infos(ClusterInfo *cluster)
 
 	snprintf(query, sizeof(query),
 			 "SELECT d.oid, d.datname, d.encoding, d.datcollate, d.datctype, ");
-	if (GET_MAJOR_VERSION(cluster->major_version) < 1500)
+	if (GET_MAJOR_VERSION(cluster->major_version) >= 1700)
+		snprintf(query + strlen(query), sizeof(query) - strlen(query),
+				 "datlocprovider, datlocale, ");
+	else if (GET_MAJOR_VERSION(cluster->major_version) >= 1500)
 		snprintf(query + strlen(query), sizeof(query) - strlen(query),
-				 "'c' AS datlocprovider, NULL AS daticulocale, ");
+				 "datlocprovider, daticulocale AS datlocale, ");
 	else
 		snprintf(query + strlen(query), sizeof(query) - strlen(query),
-				 "datlocprovider, daticulocale, ");
+				 "'c' AS datlocprovider, NULL AS datlocale, ");
 	snprintf(query + strlen(query), sizeof(query) - strlen(query),
 			 "pg_catalog.pg_tablespace_location(t.oid) AS spclocation "
 			 "FROM pg_catalog.pg_database d "
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 14a36f0503..fdea0c45a4 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -391,7 +391,7 @@ setup(char *argv0, bool *live_check)
  * Copy locale and encoding information into the new cluster's template0.
  *
  * We need to copy the encoding, datlocprovider, datcollate, datctype, and
- * daticulocale. We don't need datcollversion because that's never set for
+ * datlocale. We don't need datcollversion because that's never set for
  * template0.
  */
 static void
@@ -400,7 +400,7 @@ set_locale_and_encoding(void)
 	PGconn	   *conn_new_template1;
 	char	   *datcollate_literal;
 	char	   *datctype_literal;
-	char	   *daticulocale_literal = NULL;
+	char	   *datlocale_literal = NULL;
 	DbLocaleInfo *locale = old_cluster.template0;
 
 	prep_status("Setting locale and encoding for new cluster");
@@ -414,15 +414,29 @@ set_locale_and_encoding(void)
 	datctype_literal = PQescapeLiteral(conn_new_template1,
 									   locale->db_ctype,
 									   strlen(locale->db_ctype));
-	if (locale->db_iculocale)
-		daticulocale_literal = PQescapeLiteral(conn_new_template1,
-											   locale->db_iculocale,
-											   strlen(locale->db_iculocale));
+	if (locale->db_locale)
+		datlocale_literal = PQescapeLiteral(conn_new_template1,
+											locale->db_locale,
+											strlen(locale->db_locale));
 	else
-		daticulocale_literal = pg_strdup("NULL");
+		datlocale_literal = pg_strdup("NULL");
 
 	/* update template0 in new cluster */
-	if (GET_MAJOR_VERSION(new_cluster.major_version) >= 1500)
+	if (GET_MAJOR_VERSION(new_cluster.major_version) >= 1700)
+		PQclear(executeQueryOrDie(conn_new_template1,
+								  "UPDATE pg_catalog.pg_database "
+								  "  SET encoding = %d, "
+								  "      datlocprovider = '%c', "
+								  "      datcollate = %s, "
+								  "      datctype = %s, "
+								  "      datlocale = %s "
+								  "  WHERE datname = 'template0' ",
+								  locale->db_encoding,
+								  locale->db_collprovider,
+								  datcollate_literal,
+								  datctype_literal,
+								  datlocale_literal));
+	else if (GET_MAJOR_VERSION(new_cluster.major_version) >= 1500)
 		PQclear(executeQueryOrDie(conn_new_template1,
 								  "UPDATE pg_catalog.pg_database "
 								  "  SET encoding = %d, "
@@ -435,7 +449,7 @@ set_locale_and_encoding(void)
 								  locale->db_collprovider,
 								  datcollate_literal,
 								  datctype_literal,
-								  daticulocale_literal));
+								  datlocale_literal));
 	else
 		PQclear(executeQueryOrDie(conn_new_template1,
 								  "UPDATE pg_catalog.pg_database "
@@ -449,7 +463,7 @@ set_locale_and_encoding(void)
 
 	PQfreemem(datcollate_literal);
 	PQfreemem(datctype_literal);
-	PQfreemem(daticulocale_literal);
+	PQfreemem(datlocale_literal);
 
 	PQfinish(conn_new_template1);
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index a1d08c3dab..bc40b88782 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -206,7 +206,7 @@ typedef struct
 	char	   *db_collate;
 	char	   *db_ctype;
 	char		db_collprovider;
-	char	   *db_iculocale;
+	char	   *db_locale;
 	int			db_encoding;
 } DbLocaleInfo;
 
diff --git a/src/bin/pg_upgrade/t/002_pg_upgrade.pl b/src/bin/pg_upgrade/t/002_pg_upgrade.pl
index d951ed3af0..ec7b244d4f 100644
--- a/src/bin/pg_upgrade/t/002_pg_upgrade.pl
+++ b/src/bin/pg_upgrade/t/002_pg_upgrade.pl
@@ -104,6 +104,8 @@ if ($oldnode->pg_version >= 11)
 	push @custom_opts, '--allow-group-access';
 }
 
+my $oldversion = int($oldnode->pg_version =~ s/([0-9]*).*/$1/rg);
+
 # Set up the locale settings for the original cluster, so that we
 # can test that pg_upgrade copies the locale settings of template0
 # from the old to the new cluster.
@@ -113,11 +115,18 @@ my $original_provider = "c";
 my $original_locale = "C";
 my $original_iculocale = "";
 my $provider_field = "'c' AS datlocprovider";
-my $iculocale_field = "NULL AS daticulocale";
-if ($oldnode->pg_version >= 15 && $ENV{with_icu} eq 'yes')
+my $iculocale_field = "NULL AS datlocale";
+if ($oldversion >= 15 && $ENV{with_icu} eq 'yes')
 {
 	$provider_field = "datlocprovider";
-	$iculocale_field = "daticulocale";
+	if ($oldversion >= 17)
+	{
+		$iculocale_field = "datlocale";
+	}
+	else
+	{
+		$iculocale_field = "daticulocale AS datlocale";
+	}
 	$original_provider = "i";
 	$original_iculocale = "fr-CA";
 }
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 37f9516320..254fce8ff1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -937,14 +937,18 @@ listAllDbs(const char *pattern, bool verbose)
 					  "  d.datctype as \"%s\",\n",
 					  gettext_noop("Collate"),
 					  gettext_noop("Ctype"));
-	if (pset.sversion >= 150000)
+	if (pset.sversion >= 170000)
+		appendPQExpBuffer(&buf,
+						  "  d.datlocale as \"%s\",\n",
+						  gettext_noop("Locale"));
+	else if (pset.sversion >= 150000)
 		appendPQExpBuffer(&buf,
 						  "  d.daticulocale as \"%s\",\n",
-						  gettext_noop("ICU Locale"));
+						  gettext_noop("Locale"));
 	else
 		appendPQExpBuffer(&buf,
 						  "  NULL as \"%s\",\n",
-						  gettext_noop("ICU Locale"));
+						  gettext_noop("Locale"));
 	if (pset.sversion >= 160000)
 		appendPQExpBuffer(&buf,
 						  "  d.daticurules as \"%s\",\n",
@@ -4975,14 +4979,18 @@ listCollations(const char *pattern, bool verbose, bool showSystem)
 					  gettext_noop("Collate"),
 					  gettext_noop("Ctype"));
 
-	if (pset.sversion >= 150000)
+	if (pset.sversion >= 170000)
+		appendPQExpBuffer(&buf,
+						  "  c.colllocale AS \"%s\",\n",
+						  gettext_noop("Locale"));
+	else if (pset.sversion >= 150000)
 		appendPQExpBuffer(&buf,
 						  "  c.colliculocale AS \"%s\",\n",
-						  gettext_noop("ICU Locale"));
+						  gettext_noop("Locale"));
 	else
 		appendPQExpBuffer(&buf,
 						  "  c.collcollate AS \"%s\",\n",
-						  gettext_noop("ICU Locale"));
+						  gettext_noop("Locale"));
 
 	if (pset.sversion >= 160000)
 		appendPQExpBuffer(&buf,
diff --git a/src/include/catalog/pg_collation.dat b/src/include/catalog/pg_collation.dat
index 10c363d2ee..7396ff10c4 100644
--- a/src/include/catalog/pg_collation.dat
+++ b/src/include/catalog/pg_collation.dat
@@ -29,6 +29,6 @@
 { oid => '963',
   descr => 'sorts using the Unicode Collation Algorithm with default settings',
   collname => 'unicode', collprovider => 'i', collencoding => '-1',
-  colliculocale => 'und' },
+  colllocale => 'und' },
 
 ]
diff --git a/src/include/catalog/pg_collation.h b/src/include/catalog/pg_collation.h
index 744e64c777..1ee2d264a1 100644
--- a/src/include/catalog/pg_collation.h
+++ b/src/include/catalog/pg_collation.h
@@ -42,7 +42,7 @@ CATALOG(pg_collation,3456,CollationRelationId)
 #ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		collcollate BKI_DEFAULT(_null_);	/* LC_COLLATE setting */
 	text		collctype BKI_DEFAULT(_null_);	/* LC_CTYPE setting */
-	text		colliculocale BKI_DEFAULT(_null_);	/* ICU locale ID */
+	text		colllocale BKI_DEFAULT(_null_);	/* locale ID */
 	text		collicurules BKI_DEFAULT(_null_);	/* ICU collation rules */
 	text		collversion BKI_DEFAULT(_null_);	/* provider-dependent
 													 * version of collation
@@ -91,7 +91,7 @@ extern Oid	CollationCreate(const char *collname, Oid collnamespace,
 							bool collisdeterministic,
 							int32 collencoding,
 							const char *collcollate, const char *collctype,
-							const char *colliculocale,
+							const char *colllocale,
 							const char *collicurules,
 							const char *collversion,
 							bool if_not_exists,
diff --git a/src/include/catalog/pg_database.dat b/src/include/catalog/pg_database.dat
index 4306e8a3e8..c2ba636f8d 100644
--- a/src/include/catalog/pg_database.dat
+++ b/src/include/catalog/pg_database.dat
@@ -18,7 +18,7 @@
   datlocprovider => 'LOCALE_PROVIDER', datistemplate => 't',
   datallowconn => 't', dathasloginevt => 'f', datconnlimit => '-1', datfrozenxid => '0',
   datminmxid => '1', dattablespace => 'pg_default', datcollate => 'LC_COLLATE',
-  datctype => 'LC_CTYPE', daticulocale => 'ICU_LOCALE',
+  datctype => 'LC_CTYPE', datlocale => 'DATLOCALE',
   daticurules => 'ICU_RULES', datacl => '_null_' },
 
 ]
diff --git a/src/include/catalog/pg_database.h b/src/include/catalog/pg_database.h
index f0ed776b60..65a5635275 100644
--- a/src/include/catalog/pg_database.h
+++ b/src/include/catalog/pg_database.h
@@ -75,7 +75,7 @@ CATALOG(pg_database,1262,DatabaseRelationId) BKI_SHARED_RELATION BKI_ROWTYPE_OID
 	text		datctype BKI_FORCE_NOT_NULL;
 
 	/* ICU locale ID */
-	text		daticulocale;
+	text		datlocale;
 
 	/* ICU collation rules */
 	text		daticurules;
diff --git a/src/test/regress/expected/collate.icu.utf8.out b/src/test/regress/expected/collate.icu.utf8.out
index 7a05c75967..8ca93f4dea 100644
--- a/src/test/regress/expected/collate.icu.utf8.out
+++ b/src/test/regress/expected/collate.icu.utf8.out
@@ -1024,7 +1024,7 @@ SET icu_validation_level = disabled;
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test0 (provider = icu, locale = ' ||
-          quote_literal((SELECT CASE WHEN datlocprovider='i' THEN daticulocale ELSE datcollate END FROM pg_database WHERE datname = current_database())) || ');';
+          quote_literal((SELECT CASE WHEN datlocprovider='i' THEN datlocale ELSE datcollate END FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test0 FROM "C"; -- fail, duplicate name
@@ -1032,7 +1032,7 @@ ERROR:  collation "test0" already exists
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test1 (provider = icu, locale = ' ||
-          quote_literal((SELECT CASE WHEN datlocprovider='i' THEN daticulocale ELSE datcollate END FROM pg_database WHERE datname = current_database())) || ');';
+          quote_literal((SELECT CASE WHEN datlocprovider='i' THEN datlocale ELSE datcollate END FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 RESET icu_validation_level;
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 4f3fd46420..2235c24729 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6220,9 +6220,9 @@ List of schemas
 (0 rows)
 
 \dO "no.such.collation"
-                                  List of collations
- Schema | Name | Provider | Collate | Ctype | ICU Locale | ICU Rules | Deterministic? 
---------+------+----------+---------+-------+------------+-----------+----------------
+                                List of collations
+ Schema | Name | Provider | Collate | Ctype | Locale | ICU Rules | Deterministic? 
+--------+------+----------+---------+-------+--------+-----------+----------------
 (0 rows)
 
 \dp "no.such.access.privilege"
@@ -6409,9 +6409,9 @@ cross-database references are not implemented: "no.such.schema"."no.such.languag
 (0 rows)
 
 \dO "no.such.schema"."no.such.collation"
-                                  List of collations
- Schema | Name | Provider | Collate | Ctype | ICU Locale | ICU Rules | Deterministic? 
---------+------+----------+---------+-------+------------+-----------+----------------
+                                List of collations
+ Schema | Name | Provider | Collate | Ctype | Locale | ICU Rules | Deterministic? 
+--------+------+----------+---------+-------+--------+-----------+----------------
 (0 rows)
 
 \dp "no.such.schema"."no.such.access.privilege"
@@ -6552,9 +6552,9 @@ List of text search templates
 (0 rows)
 
 \dO regression."no.such.schema"."no.such.collation"
-                                  List of collations
- Schema | Name | Provider | Collate | Ctype | ICU Locale | ICU Rules | Deterministic? 
---------+------+----------+---------+-------+------------+-----------+----------------
+                                List of collations
+ Schema | Name | Provider | Collate | Ctype | Locale | ICU Rules | Deterministic? 
+--------+------+----------+---------+-------+--------+-----------+----------------
 (0 rows)
 
 \dp regression."no.such.schema"."no.such.access.privilege"
diff --git a/src/test/regress/sql/collate.icu.utf8.sql b/src/test/regress/sql/collate.icu.utf8.sql
index 3db9e25913..03837de846 100644
--- a/src/test/regress/sql/collate.icu.utf8.sql
+++ b/src/test/regress/sql/collate.icu.utf8.sql
@@ -363,14 +363,14 @@ SET icu_validation_level = disabled;
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test0 (provider = icu, locale = ' ||
-          quote_literal((SELECT CASE WHEN datlocprovider='i' THEN daticulocale ELSE datcollate END FROM pg_database WHERE datname = current_database())) || ');';
+          quote_literal((SELECT CASE WHEN datlocprovider='i' THEN datlocale ELSE datcollate END FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test0 FROM "C"; -- fail, duplicate name
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test1 (provider = icu, locale = ' ||
-          quote_literal((SELECT CASE WHEN datlocprovider='i' THEN daticulocale ELSE datcollate END FROM pg_database WHERE datname = current_database())) || ');';
+          quote_literal((SELECT CASE WHEN datlocprovider='i' THEN datlocale ELSE datcollate END FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 
-- 
2.34.1