wuxiaojun
/
openGauss-server
forked from huawei/openGauss-server
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Workaround for single connect-by cases 

Offering: openGaussDev

More detail: If no rownum or level qual is present, do not create connect-by-level filter.

Signed-off-by:peijisheng peijisheng@huawei.com

Match-id-400310ecf9513b47303f71f69da642d4b44d762b
This commit is contained in:
openGaussDev 2022-03-04 12:56:56 +08:00 committed by yanghao
parent fd2bf6d4a6
commit b93d4de9ed
3 changed files with 32 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/common/backend/parser/parse_startwith.cpp
View File

@ -1091,10 +1091,12 @@ static void transformStartWithClause(StartWithTransformContext *context, SelectS
raw_expression_tree_walker((Node*)context->connectByExpr,
(bool (*)())pseudo_level_rownum_walker, (Node*)context->connectByExpr);
checkConnectByExprValidity((Node*)connectByExpr);
StartWithWalker(context, connectByExpr);
context->relInfoList = context->pstate->p_start_info;
context->connect_by_type = CONNECT_BY_LEVEL;
context->connectByLevelExpr = connectByExpr;
context->connectByOtherExpr = NULL;
if (context->connect_by_type != CONNECT_BY_PRIOR) {
context->connectByLevelExpr = connectByExpr;
context->connectByOtherExpr = NULL;
}
}
/* transform start with ... connect by's expr */

2
src/gausskernel/runtime/executor/nodeStartWithOp.cpp
View File

@ -383,7 +383,7 @@ bool CheckCycleExeception(StartWithOpState *node, TupleTableSlot *slot)
Assert (IsA(rustate, RecursiveUnionState));
if (IsConnectByLevelStartWithPlan(swplan)) {
if (IsConnectByLevelStartWithPlan(swplan) || node->sw_keyAttnum == 0) {
/* for connect by level case, we do not do cycle check */
return false;
}

46
src/test/regress/expected/sw_bugfix-2.out
View File

@ -484,17 +484,18 @@ select t1.id, t1.pid, t1.name from t1 start with not id=1 connect by prior pid=i
explain select trim(t1.name) from test_hcb_ptb t1 connect by trim(t1.name) is not null;
QUERY PLAN
--------------------------------------------------------------------------------------------------
CTE Scan on tmp_reuslt (cost=13471.92..22689.36 rows=409664 width=178)
CTE Scan on tmp_reuslt (cost=13473.52..22690.96 rows=409664 width=178)
CTE tmp_reuslt
-> StartWith Operator (cost=0.00..13471.92 rows=409664 width=102)
-> StartWith Operator (cost=0.00..13473.52 rows=409664 width=102)
Start With pseudo atts: RUITR
-> Recursive Union (cost=0.00..13471.92 rows=409664 width=102)
-> Recursive Union (cost=0.00..13473.52 rows=409664 width=102)
-> Seq Scan on test_hcb_ptb t1 (cost=0.00..2.64 rows=64 width=102)
-> Nested Loop (cost=0.00..527.60 rows=40960 width=102)
-> Nested Loop (cost=0.00..527.76 rows=40960 width=102)
-> WorkTable Scan on tmp_reuslt (cost=0.00..12.80 rows=640 width=0)
-> Materialize (cost=0.00..2.96 rows=64 width=102)
-> Seq Scan on test_hcb_ptb t1 (cost=0.00..2.64 rows=64 width=102)
(10 rows)
-> Materialize (cost=0.00..3.12 rows=64 width=102)
-> Seq Scan on test_hcb_ptb t1 (cost=0.00..2.80 rows=64 width=102)
Filter: (btrim((name)::text) IS NOT NULL)
(11 rows)
/* fix create table as with start with */
create table ct as select t1.id,t1.pid,t1.name,level from test_hcb_ptb t1 start with id=141 connect by prior id=pid;
@ -1252,21 +1253,23 @@ explain performance select * from sw_dummy connect by level < 50;
drop table sw_dummy;
--test null pointers in connect by walker
explain select * from t1 connect by exists(select distinct (select id from t1));
QUERY PLAN
-------------------------------------------------------------------------------------------
CTE Scan on tmp_reuslt (cost=293.65..455.83 rows=8109 width=40)
QUERY PLAN
-------------------------------------------------------------------------------------------------
CTE Scan on tmp_reuslt (cost=293.75..455.93 rows=8109 width=40)
CTE tmp_reuslt
-> StartWith Operator (cost=0.00..293.64 rows=8109 width=10)
-> StartWith Operator (cost=0.00..293.75 rows=8109 width=10)
Start With pseudo atts: RUITR
-> Recursive Union (cost=0.00..293.64 rows=8109 width=10)
-> Recursive Union (cost=0.00..293.75 rows=8109 width=10)
-> Seq Scan on t1 (cost=0.00..1.09 rows=9 width=10)
-> Nested Loop (cost=0.00..13.04 rows=810 width=10)
-> WorkTable Scan on tmp_reuslt (cost=0.00..1.80 rows=90 width=0)
-> Materialize (cost=0.00..1.14 rows=9 width=10)
-> Seq Scan on t1 (cost=0.00..1.09 rows=9 width=10)
InitPlan 2 (returns $2)
-> Result (cost=0.00..0.01 rows=1 width=0)
(12 rows)
-> Result (cost=0.01..13.05 rows=810 width=10)
One-Time Filter: $1
InitPlan 1 (returns $1)
-> Result (cost=0.00..0.01 rows=1 width=0)
-> Nested Loop (cost=0.00..13.04 rows=810 width=10)
-> WorkTable Scan on tmp_reuslt (cost=0.00..1.80 rows=90 width=0)
-> Materialize (cost=0.00..1.14 rows=9 width=10)
-> Seq Scan on t1 (cost=0.00..1.09 rows=9 width=10)
(14 rows)
--test join + where for start with .. connect by
select t1.id,t1.pid,t2.id from test_hcb_ptb t1 join test_hcb_ptb t2 on t1.id=t2.id where t1.id>1 start with t1.id=141 connect by prior t2.id=t1.pid;
@ -1357,4 +1360,7 @@ WHERE true CONNECT BY EXISTS (
test_hcb_ptb as ref_7
)
LIMIT 169;
ERROR: Unsupported subquery found in connect by clause.
c0
----
(0 rows)