[
https://issues.apache.org/jira/browse/CALCITE-1624?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16821194#comment-16821194
]
Vineet Garg commented on CALCITE-1624:
--------------------------------------
[~danny0405] Sure go ahead. You might want to confirm if this is still an issue.
> Inefficient plan for NOT IN correlated subqueries
> -------------------------------------------------
>
> Key: CALCITE-1624
> URL: https://issues.apache.org/jira/browse/CALCITE-1624
> Project: Calcite
> Issue Type: Bug
> Components: core
> Reporter: Vineet Garg
> Priority: Major
>
> I just noticed that {{NOT IN}} correlated subqueries produces an extra
> un-neccessary join after de-correlation (this is an addition to un-necessary
> joins reported in CALCITE-1494)
> Query
> {code:SQL}
> select sal from emp
> where empno NOT IN (
> select deptno from dept
> where emp.job = dept.name)
> {code}
> Plan after subquery remove rule:
> {code}
> LogicalProject(SAL=[$5])
> LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4],
> SAL=[$5], COMM=[$6], DEPTNO=[$7], SLACKER=[$8])
> LogicalFilter(condition=[NOT(CASE(=($9, 0), false, IS NOT NULL($12),
> true, <($10, $9), true, false))])
> LogicalCorrelate(correlation=[$cor0], joinType=[LEFT],
> requiredColumns=[{2}])
> LogicalCorrelate(correlation=[$cor0], joinType=[LEFT],
> requiredColumns=[{2}])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]])
> LogicalAggregate(group=[{}], c=[COUNT()], ck=[COUNT($0)])
> LogicalProject(DEPTNO=[$0])
> LogicalFilter(condition=[=($cor0.JOB, $1)])
> LogicalTableScan(table=[[CATALOG, SALES, DEPT]])
> LogicalFilter(condition=[=($cor0.EMPNO, $0)])
> LogicalAggregate(group=[{0, 1}])
> LogicalProject(DEPTNO=[$0], i=[true])
> LogicalProject(DEPTNO=[$0])
> LogicalFilter(condition=[=($cor0.JOB, $1)])
> LogicalTableScan(table=[[CATALOG, SALES, DEPT]])
> {code}
> Plan after de-correlation
> {code}
> LogicalProject(SAL=[$5])
> LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4],
> SAL=[$5], COMM=[$6], DEPTNO=[$7], SLACKER=[$8])
> LogicalFilter(condition=[NOT(CASE(=($10, 0), false, IS NOT NULL($14),
> true, <($11, $10), true, false))])
> LogicalJoin(condition=[AND(=($0, $15), =($2, $13))], joinType=[left])
> LogicalJoin(condition=[=($2, $9)], joinType=[left])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]])
> LogicalAggregate(group=[{0}], c=[COUNT()], ck=[COUNT($1)])
> LogicalProject(JOB=[$1], DEPTNO=[$0])
> LogicalProject(DEPTNO=[$0], JOB=[$2])
> LogicalJoin(condition=[=($2, $1)], joinType=[inner])
> LogicalTableScan(table=[[CATALOG, SALES, DEPT]])
> LogicalAggregate(group=[{0}])
> LogicalProject(JOB=[$2])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]])
> LogicalJoin(condition=[=($3, $0)], joinType=[inner]) // <==
> Un-necessary join
> LogicalProject(DEPTNO=[$0], JOB=[$1], $f2=[true])
> LogicalAggregate(group=[{0, 1}])
> LogicalProject(DEPTNO=[$0], JOB=[$2], i=[$1])
> LogicalProject(DEPTNO=[$0], i=[true], JOB=[$1])
> LogicalProject(DEPTNO=[$0], JOB=[$2])
> LogicalJoin(condition=[=($2, $1)], joinType=[inner])
> LogicalTableScan(table=[[CATALOG, SALES, DEPT]])
> LogicalAggregate(group=[{0}])
> LogicalProject(JOB=[$2])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]])
> LogicalAggregate(group=[{0}])
> LogicalProject(EMPNO=[$0])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]])
> {code}
> As you can see in plan after de-correlation there is an un-necessary inner
> join.
> This is not reproducible on CALCITE-1494's branch. But since this is a
> separate issue from CALCITE-1494 I decided to open a separate JIRA.
> Feel free to mark is duplicate or close it if you think otherwise.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
