From a7cd9e56e7b6b3bf55621c7bc701d033cc8ca0cc Mon Sep 17 00:00:00 2001 From: cc_db_dev Date: Tue, 13 Aug 2024 18:04:49 +0800 Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8Dinlist=20to=20join=20+=20for?= =?UTF-8?q?=20update=20=E5=9C=BA=E6=99=AF=E4=B8=8B=E7=9A=84=E5=AE=95?= =?UTF-8?q?=E6=9C=BA=E9=97=AE=E9=A2=98?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 根因分析： 在inlist to join优化中，如果被优化的目标表为for update/share的操作目标，处理逻辑有误 解决方案： (1)在inlist to join中，如果存在for update作用于基表，此时plan中的rowmarks会被标记为RowMarkRequiresRowShareLock，但是在 inist2join_qrw_optimization优化中，会将该目标表改为subquen加入到可选路径中，对于子查询而言，此时plan中的标记不能被标记为RowMarkRequiresRowshareLock, 应该被标记为仅引用或者复制，但此时尚未选择哪种路径（扫描基表或者子查询），也即无法确定rowmarks中的值，所以冲突，目前将此种场景下的优化禁止。 (2)在inlist to join中，如果for update作用于子查询，此时的rowmark跟变换成子查询后一致，可以继续进行优化。 --- .../optimizer/plan/planrewrite.cpp | 14 +++ src/test/regress/expected/query_rewrite.out | 103 ++++++++++++++++++ src/test/regress/sql/query_rewrite.sql | 42 +++++++ 3 files changed, 159 insertions(+) diff --git a/src/gausskernel/optimizer/plan/planrewrite.cpp b/src/gausskernel/optimizer/plan/planrewrite.cpp index 98e98d91f..f4ae1074b 100644 --- a/src/gausskernel/optimizer/plan/planrewrite.cpp +++ b/src/gausskernel/optimizer/plan/planrewrite.cpp @@ -165,6 +165,20 @@ void inlist2join_qrw_optimization(PlannerInfo* root, int rti) return; } + /* + * if rowmarks effect on this rel is true lock, + * bypass inlist optimize to avoid conflict + */ + ListCell* lc = NULL; + foreach(lc, root->rowMarks) { + PlanRowMark* rc = (PlanRowMark*)lfirst(lc); + if ((int)rc->rti == rti) { + if (RowMarkRequiresRowShareLock(rc->markType)) { + return; + } + } + } + /* * Return directly if inlist2join optimization can not apply to current rel, * [1]. When inlist2join optimization is not enabled diff --git a/src/test/regress/expected/query_rewrite.out b/src/test/regress/expected/query_rewrite.out index 2fceeef55..99fa58c3f 100755 --- a/src/test/regress/expected/query_rewrite.out +++ b/src/test/regress/expected/query_rewrite.out @@ -336,6 +336,109 @@ SELECT 1 FROM ( SELECT 1 FROM table1 WHERE NOT EXISTS ( SELECT 1 WHERE column63 (1 row) drop table table1; +--test for update + inlist to join bug +reset all; +set current_schema = query_rewrite; +set qrw_inlist2join_optmode = 'rule_base'; +create table test_forupdate(a int,b int,c text); +create table test_helper(a int, b int, c text); +insert into test_forupdate values(1,1,'test'); +insert into test_helper values(1,1,'bbbtest'); +explain (costs off) select * from test_forupdate where a in (1,2,3,4, 5,6,7,8,9,10,11,12); + QUERY PLAN +-------------------------------------------------------------------- + Hash Join + Hash Cond: (query_rewrite.test_forupdate.a = "*VALUES*".column1) + -> Seq Scan on test_forupdate + -> Hash + -> HashAggregate + Group By Key: "*VALUES*".column1 + -> Values Scan on "*VALUES*" +(7 rows) + +select * from test_forupdate where a in(1,2,3,4,5,6,7,8,9,10,11,12); + a | b | c +---+---+------ + 1 | 1 | test +(1 row) + +--can not inlist to join +explain (costs off) select * from test_forupdate where a in (1,2,3,4,5,6,7,8,9,10,11,12) for update; + QUERY PLAN +----------------------------------------------------------------------- + LockRows + -> Seq Scan on test_forupdate + Filter: (a = ANY ('{1,2,3,4,5,6,7,8,9,10,11,12}'::integer[])) +(3 rows) + +select * from test_forupdate where a in (1,2,3,4,5,6,7,8,9,10,11,12) for update; + a | b | c +---+---+------ + 1 | 1 | test +(1 row) + +--not target table,ok +explain (costs off) select * from test_forupdate,test_helper where test_forupdate.a in (1,2,3,4,5,6,7,8,9,10,11,12) for update of test_helper; + QUERY PLAN +-------------------------------------------------------------------------------------- + LockRows + -> Nested Loop + -> Seq Scan on test_helper + -> Materialize + -> Hash Join + Hash Cond: (query_rewrite.test_forupdate.a = "*VALUES*".column1) + -> Seq Scan on test_forupdate + -> Hash + -> HashAggregate + Group By Key: "*VALUES*".column1 + -> Values Scan on "*VALUES*" +(11 rows) + +select * from test_forupdate,test_helper where test_forupdate.a in (1,2,3,4,5,6,7,8,9,10,11,12) for update of test_helper; + a | b | c | a | b | c +---+---+------+---+---+--------- + 1 | 1 | test | 1 | 1 | bbbtest +(1 row) + +--subquery,target table,ok +explain (costs off) select * from (select * from test_forupdate limit 1) where a in (1,2,3,4,5,6,7,8,9,10,11,12) for update; + QUERY PLAN +------------------------------------------------------------------------ + LockRows + -> Subquery Scan on __unnamed_subquery__ + -> Hash Right Semi Join + Hash Cond: ("*VALUES*".column1 = __unnamed_subquery__.a) + -> Values Scan on "*VALUES*" + -> Hash + -> Subquery Scan on __unnamed_subquery__ + -> Limit + -> LockRows + -> Seq Scan on test_forupdate +(10 rows) + +select * from (select * from test_forupdate limit 1) where a in (1,2,3,4,5,6,7,8,9,10,11,12) for update; + a | b | c +---+---+------ + 1 | 1 | test +(1 row) + +--test bug scene,concurrent update +\parallel on 2 +begin + set qrw_inlist2join_optmode = 'rule_base'; + perform pg_sleep(3); + perform c,a from test_forupdate where a in (1,2,3,4,5,6,7,8,9,10,11,12) for update; +end; +/ +begin + update test_forupdate set b=10 where a=1; + perform pg_sleep(3); +end; +/ +\parallel off +drop table test_forupdate; +drop table test_helper; +reset qrw_inlist2join_optmode; drop schema query_rewrite cascade; NOTICE: drop cascades to 7 other objects DETAIL: drop cascades to table t3 diff --git a/src/test/regress/sql/query_rewrite.sql b/src/test/regress/sql/query_rewrite.sql index a44e11d5b..3775774ad 100644 --- a/src/test/regress/sql/query_rewrite.sql +++ b/src/test/regress/sql/query_rewrite.sql @@ -194,5 +194,47 @@ insert into table1 values(4,4); SELECT 1 FROM ( SELECT 1 FROM table1 WHERE NOT EXISTS ( SELECT 1 WHERE column63 = column44 ) ) AS alias1 ; drop table table1; +--test for update + inlist to join bug +reset all; +set current_schema = query_rewrite; +set qrw_inlist2join_optmode = 'rule_base'; + + +create table test_forupdate(a int,b int,c text); +create table test_helper(a int, b int, c text); +insert into test_forupdate values(1,1,'test'); +insert into test_helper values(1,1,'bbbtest'); + +explain (costs off) select * from test_forupdate where a in (1,2,3,4, 5,6,7,8,9,10,11,12); +select * from test_forupdate where a in(1,2,3,4,5,6,7,8,9,10,11,12); +--can not inlist to join +explain (costs off) select * from test_forupdate where a in (1,2,3,4,5,6,7,8,9,10,11,12) for update; +select * from test_forupdate where a in (1,2,3,4,5,6,7,8,9,10,11,12) for update; +--not target table,ok +explain (costs off) select * from test_forupdate,test_helper where test_forupdate.a in (1,2,3,4,5,6,7,8,9,10,11,12) for update of test_helper; +select * from test_forupdate,test_helper where test_forupdate.a in (1,2,3,4,5,6,7,8,9,10,11,12) for update of test_helper; +--subquery,target table,ok +explain (costs off) select * from (select * from test_forupdate limit 1) where a in (1,2,3,4,5,6,7,8,9,10,11,12) for update; +select * from (select * from test_forupdate limit 1) where a in (1,2,3,4,5,6,7,8,9,10,11,12) for update; + +--test bug scene,concurrent update +\parallel on 2 +begin + set qrw_inlist2join_optmode = 'rule_base'; + perform pg_sleep(3); + perform c,a from test_forupdate where a in (1,2,3,4,5,6,7,8,9,10,11,12) for update; +end; +/ + +begin + update test_forupdate set b=10 where a=1; + perform pg_sleep(3); +end; +/ +\parallel off +drop table test_forupdate; +drop table test_helper; +reset qrw_inlist2join_optmode; + drop schema query_rewrite cascade; reset current_schema;