From: Alvaro Herrera Date: Tue, 27 Oct 2020 16:49:19 +0000 (-0300) Subject: Accept relations of any kind in LOCK TABLE X-Git-Tag: REL_14_BETA1~1417 X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=59ab4ac32460a6a93b665f4e487d7ff64979ba4d;p=postgresql.git Accept relations of any kind in LOCK TABLE The restriction that only tables and views can be locked by LOCK TABLE is quite arbitrary, since the underlying mechanism can lock any relation type. Drop the restriction so that programs such as pg_dump can lock all relations they're interested in, preventing schema changes that could cause a dump to fail after expending much effort. Backpatch to 9.5. Author: Álvaro Herrera Reviewed-by: Tom Lane Reported-by: Wells Oliver Discussion: https://postgr.es/m/20201021200659.GA32358@alvherre.pgsql --- diff --git a/doc/src/sgml/ref/lock.sgml b/doc/src/sgml/ref/lock.sgml index 4cdfae2279e..37881f25ac5 100644 --- a/doc/src/sgml/ref/lock.sgml +++ b/doc/src/sgml/ref/lock.sgml @@ -16,7 +16,7 @@ PostgreSQL documentation LOCK - lock a table + lock a named relation (table, etc) @@ -34,7 +34,9 @@ LOCK [ TABLE ] [ ONLY ] name [ * ] Description - LOCK TABLE obtains a table-level lock, waiting + LOCK TABLE obtains a table-level lock on a + relation (table, partitioned table, foreign table, view, + materialized view, index, composite type, sequence), waiting if necessary for any conflicting locks to be released. If NOWAIT is specified, LOCK TABLE does not wait to acquire the desired lock: if it @@ -115,17 +117,18 @@ LOCK [ TABLE ] [ ONLY ] name [ * ] name - The name (optionally schema-qualified) of an existing table to - lock. If ONLY is specified before the table name, only that + The name (optionally schema-qualified) of an existing relation to + lock. If ONLY is specified before a table name, only that table is locked. If ONLY is not specified, the table and all its descendant tables (if any) are locked. Optionally, * can be specified after the table name to explicitly indicate that - descendant tables are included. + descendant tables are included. When locking a view, all relations appearing + in the view definition are locked, regardless of ONLY. The command LOCK TABLE a, b; is equivalent to - LOCK TABLE a; LOCK TABLE b;. The tables are locked + LOCK TABLE a; LOCK TABLE b;. The relations are locked one-by-one in the order specified in the LOCK TABLE command. diff --git a/src/backend/commands/lockcmds.c b/src/backend/commands/lockcmds.c index d8cafc42bb5..f64246dba39 100644 --- a/src/backend/commands/lockcmds.c +++ b/src/backend/commands/lockcmds.c @@ -83,14 +83,6 @@ RangeVarCallbackForLockTable(const RangeVar *rv, Oid relid, Oid oldrelid, return; /* woops, concurrently dropped; no permissions * check */ - /* Currently, we only allow plain tables or views to be locked */ - if (relkind != RELKIND_RELATION && relkind != RELKIND_PARTITIONED_TABLE && - relkind != RELKIND_VIEW) - ereport(ERROR, - (errcode(ERRCODE_WRONG_OBJECT_TYPE), - errmsg("\"%s\" is not a table or view", - rv->relname))); - /* * Make note if a temporary relation has been accessed in this * transaction. @@ -186,11 +178,13 @@ LockViewRecurse_walker(Node *node, LockViewRecurse_context *context) foreach(rtable, query->rtable) { RangeTblEntry *rte = lfirst(rtable); + Oid relid; AclResult aclresult; - Oid relid = rte->relid; - char relkind = rte->relkind; - char *relname = get_rel_name(relid); + /* ignore all non-relation RTEs */ + if (rte->rtekind != RTE_RELATION) + continue; + relid = rte->relid; /* * The OLD and NEW placeholder entries in the view's rtable are @@ -201,11 +195,6 @@ LockViewRecurse_walker(Node *node, LockViewRecurse_context *context) strcmp(rte->eref->aliasname, "new") == 0)) continue; - /* Currently, we only allow plain tables or views to be locked. */ - if (relkind != RELKIND_RELATION && relkind != RELKIND_PARTITIONED_TABLE && - relkind != RELKIND_VIEW) - continue; - /* Check infinite recursion in the view definition. */ if (list_member_oid(context->ancestor_views, relid)) ereport(ERROR, @@ -216,7 +205,8 @@ LockViewRecurse_walker(Node *node, LockViewRecurse_context *context) /* Check permissions with the view owner's privilege. */ aclresult = LockTableAclCheck(relid, context->lockmode, context->viewowner); if (aclresult != ACLCHECK_OK) - aclcheck_error(aclresult, get_relkind_objtype(relkind), relname); + aclcheck_error(aclresult, get_relkind_objtype(rte->relkind), + get_rel_name(relid)); /* We have enough rights to lock the relation; do so. */ if (!context->nowait) @@ -225,9 +215,9 @@ LockViewRecurse_walker(Node *node, LockViewRecurse_context *context) ereport(ERROR, (errcode(ERRCODE_LOCK_NOT_AVAILABLE), errmsg("could not obtain lock on relation \"%s\"", - relname))); + get_rel_name(relid)))); - if (relkind == RELKIND_VIEW) + if (rte->relkind == RELKIND_VIEW) LockViewRecurse(relid, context->lockmode, context->nowait, context->ancestor_views); else if (rte->inh) LockTableRecurse(relid, context->lockmode, context->nowait); diff --git a/src/test/regress/expected/lock.out b/src/test/regress/expected/lock.out index 2e54688dffe..1d6a4e9f1e0 100644 --- a/src/test/regress/expected/lock.out +++ b/src/test/regress/expected/lock.out @@ -12,6 +12,9 @@ CREATE VIEW lock_view3 AS SELECT * from lock_view2; CREATE VIEW lock_view4 AS SELECT (select a from lock_tbl1a limit 1) from lock_tbl1; CREATE VIEW lock_view5 AS SELECT * from lock_tbl1 where a in (select * from lock_tbl1a); CREATE VIEW lock_view6 AS SELECT * from (select * from lock_tbl1) sub; +CREATE MATERIALIZED VIEW lock_mv1 AS SELECT * FROM lock_view6; +CREATE INDEX lock_mvi1 ON lock_mv1 (a); +CREATE SEQUENCE lock_seq; CREATE ROLE regress_rol_lock1; ALTER ROLE regress_rol_lock1 SET search_path = lock_schema1; GRANT USAGE ON SCHEMA lock_schema1 TO regress_rol_lock1; @@ -154,9 +157,16 @@ BEGIN; LOCK TABLE ONLY lock_tbl1; ROLLBACK; RESET ROLE; +-- Lock other relations +BEGIN TRANSACTION; +LOCK TABLE lock_mv1; +LOCK TABLE lock_mvi1; +LOCK TABLE lock_seq; +ROLLBACK; -- -- Clean up -- +DROP MATERIALIZED VIEW lock_mv1; DROP VIEW lock_view7; DROP VIEW lock_view6; DROP VIEW lock_view5; @@ -168,6 +178,7 @@ DROP TABLE lock_tbl3; DROP TABLE lock_tbl2; DROP TABLE lock_tbl1; DROP TABLE lock_tbl1a; +DROP SEQUENCE lock_seq; DROP SCHEMA lock_schema1 CASCADE; DROP ROLE regress_rol_lock1; -- atomic ops tests diff --git a/src/test/regress/sql/lock.sql b/src/test/regress/sql/lock.sql index e50cb6f0642..98d13fc8e1e 100644 --- a/src/test/regress/sql/lock.sql +++ b/src/test/regress/sql/lock.sql @@ -13,6 +13,9 @@ CREATE VIEW lock_view3 AS SELECT * from lock_view2; CREATE VIEW lock_view4 AS SELECT (select a from lock_tbl1a limit 1) from lock_tbl1; CREATE VIEW lock_view5 AS SELECT * from lock_tbl1 where a in (select * from lock_tbl1a); CREATE VIEW lock_view6 AS SELECT * from (select * from lock_tbl1) sub; +CREATE MATERIALIZED VIEW lock_mv1 AS SELECT * FROM lock_view6; +CREATE INDEX lock_mvi1 ON lock_mv1 (a); +CREATE SEQUENCE lock_seq; CREATE ROLE regress_rol_lock1; ALTER ROLE regress_rol_lock1 SET search_path = lock_schema1; GRANT USAGE ON SCHEMA lock_schema1 TO regress_rol_lock1; @@ -117,9 +120,18 @@ LOCK TABLE ONLY lock_tbl1; ROLLBACK; RESET ROLE; +-- Lock other relations +BEGIN TRANSACTION; +LOCK TABLE lock_mv1; +LOCK TABLE lock_mvi1; +LOCK TABLE lock_seq; +ROLLBACK; + + -- -- Clean up -- +DROP MATERIALIZED VIEW lock_mv1; DROP VIEW lock_view7; DROP VIEW lock_view6; DROP VIEW lock_view5; @@ -130,6 +142,7 @@ DROP TABLE lock_tbl3; DROP TABLE lock_tbl2; DROP TABLE lock_tbl1; DROP TABLE lock_tbl1a; +DROP SEQUENCE lock_seq; DROP SCHEMA lock_schema1 CASCADE; DROP ROLE regress_rol_lock1;