Remove pg_collation.collversion.

This model couldn't be extended to cover the default collation, and
didn't have any information about the affected database objects when the
version changed.  Remove, in preparation for a follow-up commit that
will add a new mechanism.

Author: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Discussion: https://postgr.es/m/CAEepm%3D0uEQCpfq_%2BLYFBdArCe4Ot98t1aR4eYiYTe%3DyavQygiQ%40mail.gmail.com

7 files changed, 1 insertions, 183 deletions

diff --git a/src/backend/catalog/pg_collation.c b/src/backend/catalog/pg_collation.c
index 5fdf1acb7e5..3c84378d025 100644
--- a/src/backend/catalog/pg_collation.c
+++ b/src/backend/catalog/pg_collation.c
@@ -49,7 +49,6 @@ CollationCreate(const char *collname, Oid collnamespace,
 				bool collisdeterministic,
 				int32 collencoding,
 				const char *collcollate, const char *collctype,
-				const char *collversion,
 				bool if_not_exists,
 				bool quiet)
 {
@@ -167,10 +166,6 @@ CollationCreate(const char *collname, Oid collnamespace,
 	values[Anum_pg_collation_collcollate - 1] = NameGetDatum(&name_collate);
 	namestrcpy(&name_ctype, collctype);
 	values[Anum_pg_collation_collctype - 1] = NameGetDatum(&name_ctype);
-	if (collversion)
-		values[Anum_pg_collation_collversion - 1] = CStringGetTextDatum(collversion);
-	else
-		nulls[Anum_pg_collation_collversion - 1] = true;
 
 	tup = heap_form_tuple(tupDesc, values, nulls);
 
diff --git a/src/backend/commands/collationcmds.c b/src/backend/commands/collationcmds.c
index 9f6582c530c..5ad8886e60a 100644
--- a/src/backend/commands/collationcmds.c
+++ b/src/backend/commands/collationcmds.c
@@ -61,14 +61,12 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 	DefElem    *lcctypeEl = NULL;
 	DefElem    *providerEl = NULL;
 	DefElem    *deterministicEl = NULL;
-	DefElem    *versionEl = NULL;
 	char	   *collcollate = NULL;
 	char	   *collctype = NULL;
 	char	   *collproviderstr = NULL;
 	bool		collisdeterministic = true;
 	int			collencoding = 0;
 	char		collprovider = 0;
-	char	   *collversion = NULL;
 	Oid			newoid;
 	ObjectAddress address;
 
@@ -96,8 +94,6 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 			defelp = &providerEl;
 		else if (strcmp(defel->defname, "deterministic") == 0)
 			defelp = &deterministicEl;
-		else if (strcmp(defel->defname, "version") == 0)
-			defelp = &versionEl;
 		else
 		{
 			ereport(ERROR,
@@ -166,9 +162,6 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 	if (deterministicEl)
 		collisdeterministic = defGetBoolean(deterministicEl);
 
-	if (versionEl)
-		collversion = defGetString(versionEl);
-
 	if (collproviderstr)
 	{
 		if (pg_strcasecmp(collproviderstr, "icu") == 0)
@@ -215,9 +208,6 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 		}
 	}
 
-	if (!collversion)
-		collversion = get_collation_actual_version(collprovider, collcollate);
-
 	newoid = CollationCreate(collName,
 							 collNamespace,
 							 GetUserId(),
@@ -226,7 +216,6 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 							 collencoding,
 							 collcollate,
 							 collctype,
-							 collversion,
 							 if_not_exists,
 							 false);	/* not quiet */
 
@@ -277,80 +266,6 @@ IsThereCollationInNamespace(const char *collname, Oid nspOid)
 						collname, get_namespace_name(nspOid))));
 }
 
-/*
- * ALTER COLLATION
- */
-ObjectAddress
-AlterCollation(AlterCollationStmt *stmt)
-{
-	Relation	rel;
-	Oid			collOid;
-	HeapTuple	tup;
-	Form_pg_collation collForm;
-	Datum		collversion;
-	bool		isnull;
-	char	   *oldversion;
-	char	   *newversion;
-	ObjectAddress address;
-
-	rel = table_open(CollationRelationId, RowExclusiveLock);
-	collOid = get_collation_oid(stmt->collname, false);
-
-	if (!pg_collation_ownercheck(collOid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_COLLATION,
-					   NameListToString(stmt->collname));
-
-	tup = SearchSysCacheCopy1(COLLOID, ObjectIdGetDatum(collOid));
-	if (!HeapTupleIsValid(tup))
-		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);
-
-	newversion = get_collation_actual_version(collForm->collprovider, NameStr(collForm->collcollate));
-
-	/* cannot change from NULL to non-NULL or vice versa */
-	if ((!oldversion && newversion) || (oldversion && !newversion))
-		elog(ERROR, "invalid collation version change");
-	else if (oldversion && newversion && strcmp(newversion, oldversion) != 0)
-	{
-		bool		nulls[Natts_pg_collation];
-		bool		replaces[Natts_pg_collation];
-		Datum		values[Natts_pg_collation];
-
-		ereport(NOTICE,
-				(errmsg("changing version from %s to %s",
-						oldversion, newversion)));
-
-		memset(values, 0, sizeof(values));
-		memset(nulls, false, sizeof(nulls));
-		memset(replaces, false, sizeof(replaces));
-
-		values[Anum_pg_collation_collversion - 1] = CStringGetTextDatum(newversion);
-		replaces[Anum_pg_collation_collversion - 1] = true;
-
-		tup = heap_modify_tuple(tup, RelationGetDescr(rel),
-								values, nulls, replaces);
-	}
-	else
-		ereport(NOTICE,
-				(errmsg("version has not changed")));
-
-	CatalogTupleUpdate(rel, &tup->t_self, tup);
-
-	InvokeObjectPostAlterHook(CollationRelationId, collOid, 0);
-
-	ObjectAddressSet(address, CollationRelationId, collOid);
-
-	heap_freetuple(tup);
-	table_close(rel, NoLock);
-
-	return address;
-}
-
-
 Datum
 pg_collation_actual_version(PG_FUNCTION_ARGS)
 {
@@ -608,7 +523,6 @@ pg_import_system_collations(PG_FUNCTION_ARGS)
 			collid = CollationCreate(localebuf, nspid, GetUserId(),
 									 COLLPROVIDER_LIBC, true, enc,
 									 localebuf, localebuf,
-									 get_collation_actual_version(COLLPROVIDER_LIBC, localebuf),
 									 true, true);
 			if (OidIsValid(collid))
 			{
@@ -669,7 +583,6 @@ pg_import_system_collations(PG_FUNCTION_ARGS)
 			collid = CollationCreate(alias, nspid, GetUserId(),
 									 COLLPROVIDER_LIBC, true, enc,
 									 locale, locale,
-									 get_collation_actual_version(COLLPROVIDER_LIBC, locale),
 									 true, true);
 			if (OidIsValid(collid))
 			{
@@ -731,7 +644,6 @@ pg_import_system_collations(PG_FUNCTION_ARGS)
 									 nspid, GetUserId(),
 									 COLLPROVIDER_ICU, true, -1,
 									 collcollate, collcollate,
-									 get_collation_actual_version(COLLPROVIDER_ICU, collcollate),
 									 true, true);
 			if (OidIsValid(collid))
 			{
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 2b4d7654cc7..ac8b57109c5 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -3224,16 +3224,6 @@ _copyAlterTableCmd(const AlterTableCmd *from)
 	return newnode;
 }
 
-static AlterCollationStmt *
-_copyAlterCollationStmt(const AlterCollationStmt *from)
-{
-	AlterCollationStmt *newnode = makeNode(AlterCollationStmt);
-
-	COPY_NODE_FIELD(collname);
-
-	return newnode;
-}
-
 static AlterDomainStmt *
 _copyAlterDomainStmt(const AlterDomainStmt *from)
 {
@@ -5229,9 +5219,6 @@ copyObjectImpl(const void *from)
 		case T_AlterTableCmd:
 			retval = _copyAlterTableCmd(from);
 			break;
-		case T_AlterCollationStmt:
-			retval = _copyAlterCollationStmt(from);
-			break;
 		case T_AlterDomainStmt:
 			retval = _copyAlterDomainStmt(from);
 			break;
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index e2d1b987bf4..0cf90ef33c3 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1108,14 +1108,6 @@ _equalAlterTableCmd(const AlterTableCmd *a, const AlterTableCmd *b)
 }
 
 static bool
-_equalAlterCollationStmt(const AlterCollationStmt *a, const AlterCollationStmt *b)
-{
-	COMPARE_NODE_FIELD(collname);
-
-	return true;
-}
-
-static bool
 _equalAlterDomainStmt(const AlterDomainStmt *a, const AlterDomainStmt *b)
 {
 	COMPARE_SCALAR_FIELD(subtype);
@@ -3283,9 +3275,6 @@ equal(const void *a, const void *b)
 		case T_AlterTableCmd:
 			retval = _equalAlterTableCmd(a, b);
 			break;
-		case T_AlterCollationStmt:
-			retval = _equalAlterCollationStmt(a, b);
-			break;
 		case T_AlterDomainStmt:
 			retval = _equalAlterDomainStmt(a, b);
 			break;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 480d1683468..60cf7242a30 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -254,7 +254,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 }
 
 %type <node>	stmt schema_stmt
-		AlterEventTrigStmt AlterCollationStmt
+		AlterEventTrigStmt
 		AlterDatabaseStmt AlterDatabaseSetStmt AlterDomainStmt AlterEnumStmt
 		AlterFdwStmt AlterForeignServerStmt AlterGroupStmt
 		AlterObjectDependsStmt AlterObjectSchemaStmt AlterOwnerStmt
@@ -835,7 +835,6 @@ stmtmulti:	stmtmulti ';' stmt
 
 stmt :
 			AlterEventTrigStmt
-			| AlterCollationStmt
 			| AlterDatabaseStmt
 			| AlterDatabaseSetStmt
 			| AlterDefaultPrivilegesStmt
@@ -10171,21 +10170,6 @@ drop_option:
 
 /*****************************************************************************
  *
- *		ALTER COLLATION
- *
- *****************************************************************************/
-
-AlterCollationStmt: ALTER COLLATION any_name REFRESH VERSION_P
-				{
-					AlterCollationStmt *n = makeNode(AlterCollationStmt);
-					n->collname = $3;
-					$$ = (Node *)n;
-				}
-		;
-
-
-/*****************************************************************************
- *
  *		ALTER SYSTEM
  *
  * This is used to change configuration parameters persistently.
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 9a35147b26a..f398027fa61 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -1842,10 +1842,6 @@ ProcessUtilitySlow(ParseState *pstate,
 				address = AlterStatistics((AlterStatsStmt *) parsetree);
 				break;
 
-			case T_AlterCollationStmt:
-				address = AlterCollation((AlterCollationStmt *) parsetree);
-				break;
-
 			default:
 				elog(ERROR, "unrecognized node type: %d",
 					 (int) nodeTag(parsetree));
@@ -2993,10 +2989,6 @@ CreateCommandTag(Node *parsetree)
 			tag = CMDTAG_DROP_SUBSCRIPTION;
 			break;
 
-		case T_AlterCollationStmt:
-			tag = CMDTAG_ALTER_COLLATION;
-			break;
-
 		case T_PrepareStmt:
 			tag = CMDTAG_PREPARE;
 			break;
@@ -3609,10 +3601,6 @@ GetCommandLogLevel(Node *parsetree)
 			lev = LOGSTMT_DDL;
 			break;
 
-		case T_AlterCollationStmt:
-			lev = LOGSTMT_DDL;
-			break;
-
 			/* already-planned queries */
 		case T_PlannedStmt:
 			{
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 07299dbc091..514e0fa0af8 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -1513,8 +1513,6 @@ pg_newlocale_from_collation(Oid collid)
 		const char *collctype pg_attribute_unused();
 		struct pg_locale_struct result;
 		pg_locale_t resultp;
-		Datum		collversion;
-		bool		isnull;
 
 		tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid));
 		if (!HeapTupleIsValid(tp))
@@ -1616,41 +1614,6 @@ pg_newlocale_from_collation(Oid collid)
 #endif							/* not USE_ICU */
 		}
 
-		collversion = SysCacheGetAttr(COLLOID, tp, Anum_pg_collation_collversion,
-									  &isnull);
-		if (!isnull)
-		{
-			char	   *actual_versionstr;
-			char	   *collversionstr;
-
-			actual_versionstr = get_collation_actual_version(collform->collprovider, collcollate);
-			if (!actual_versionstr)
-			{
-				/*
-				 * This could happen when specifying a version in CREATE
-				 * COLLATION for a libc locale, or manually creating a mess in
-				 * the catalogs.
-				 */
-				ereport(ERROR,
-						(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,
-						(errmsg("collation \"%s\" has version mismatch",
-								NameStr(collform->collname)),
-						 errdetail("The collation in the database was created using version %s, "
-								   "but the operating system provides version %s.",
-								   collversionstr, actual_versionstr),
-						 errhint("Rebuild all objects affected by this collation and run "
-								 "ALTER COLLATION %s REFRESH VERSION, "
-								 "or build PostgreSQL with the right library version.",
-								 quote_qualified_identifier(get_namespace_name(collform->collnamespace),
-															NameStr(collform->collname)))));
-		}
-
 		ReleaseSysCache(tp);
 
 		/* We'll keep the pg_locale_t structures in TopMemoryContext */