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https://issues.apache.org/jira/browse/CALCITE-1495?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Vineet Garg updated CALCITE-1495:
---------------------------------
Description:
For IN and EXISTS subqueries Calcite currently generates plan consisting of
GROUP BY on inner table followed by INNER JOIN with outer table.
e.g. for following query:
{noformat} select sal from emp where empno IN (select deptno from dept)
{noformat}
Generated plan is:
{noformat}
LogicalProject(SAL=[$5])
LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4],
SAL=[$5], COMM=[$6], DEPTNO=[$7], SLACKER=[$8])
LogicalJoin(condition=[=($0, $9)], joinType=[inner])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
LogicalAggregate(group=[{0}])
LogicalProject(DEPTNO=[$0])
LogicalTableScan(table=[[CATALOG, SALES, DEPT]])
{noformat}
Such cases could be converted using this rule to use SEMI-JOIN to make it more
efficient
was:
For IN and EXISTS subqueries Calcite currently generates plan consisting of
GROUP BY on inner table followed by INNER JOIN with outer table.
e.g. for following query:
{noformat} :select sal from emp where empno IN (select deptno from dept)
{noformat}
Generated plan is:
{noformat}
LogicalProject(SAL=[$5])
LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4],
SAL=[$5], COMM=[$6], DEPTNO=[$7], SLACKER=[$8])
LogicalJoin(condition=[=($0, $9)], joinType=[inner])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
LogicalAggregate(group=[{0}])
LogicalProject(DEPTNO=[$0])
LogicalTableScan(table=[[CATALOG, SALES, DEPT]])
{noformat}
Such cases could be converted using this rule to use SEMI-JOIN to make it more
efficient
> Add a rule to convert INNER JOIN preceded by GROUP BY to appropriate SEMI-JOIN
> ------------------------------------------------------------------------------
>
> Key: CALCITE-1495
> URL: https://issues.apache.org/jira/browse/CALCITE-1495
> Project: Calcite
> Issue Type: New Feature
> Components: core
> Reporter: Vineet Garg
> Assignee: Julian Hyde
>
> For IN and EXISTS subqueries Calcite currently generates plan consisting of
> GROUP BY on inner table followed by INNER JOIN with outer table.
> e.g. for following query:
> {noformat} select sal from emp where empno IN (select deptno from dept)
> {noformat}
> Generated plan is:
> {noformat}
> LogicalProject(SAL=[$5])
> LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4],
> SAL=[$5], COMM=[$6], DEPTNO=[$7], SLACKER=[$8])
> LogicalJoin(condition=[=($0, $9)], joinType=[inner])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]])
> LogicalAggregate(group=[{0}])
> LogicalProject(DEPTNO=[$0])
> LogicalTableScan(table=[[CATALOG, SALES, DEPT]])
> {noformat}
> Such cases could be converted using this rule to use SEMI-JOIN to make it
> more efficient
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