修复inlist to join + for update 场景下的宕机问题

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。
2024-08-13 18:04:49 +08:00
parent 61e0ea88af
commit a7cd9e56e7
3 changed files with 159 additions and 0 deletions
--- 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
--- 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
--- 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;