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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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Julian Hyde updated CALCITE-1495:
---------------------------------
Description:
SemiJoinRule should not apply to RIGHT and FULL JOIN; and it should strip LEFT
JOIN once it has disovered that the rows from the right input are unique.
Original description:
bq. For IN and EXISTS sub-queries Calcite currently generates plan consisting
of GROUP BY on inner table followed by INNER JOIN with outer table. 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
> SemiJoinRule should not apply to RIGHT and FULL 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
>
> SemiJoinRule should not apply to RIGHT and FULL JOIN; and it should strip
> LEFT JOIN once it has disovered that the rows from the right input are unique.
> Original description:
> bq. For IN and EXISTS sub-queries Calcite currently generates plan consisting
> of GROUP BY on inner table followed by INNER JOIN with outer table. Such
> cases could be converted using this rule to use SEMI-JOIN to make it more
> efficient.
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