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Posted to issues@calcite.apache.org by "James Starr (Jira)" <ji...@apache.org> on 2021/06/29 22:59:00 UTC
[jira] [Updated] (CALCITE-4668) RelBuilder.join should convert
Correlate to Join if correlation variable is used
[ https://issues.apache.org/jira/browse/CALCITE-4668?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
James Starr updated CALCITE-4668:
---------------------------------
Summary: RelBuilder.join should convert Correlate to Join if correlation variable is used (was: RelBuilder.join should convert Correlate to Join if correlation variable is unused)
> RelBuilder.join should convert Correlate to Join if correlation variable is used
> --------------------------------------------------------------------------------
>
> Key: CALCITE-4668
> URL: https://issues.apache.org/jira/browse/CALCITE-4668
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Reporter: James Starr
> Priority: Major
> Labels: pull-request-available
> Time Spent: 10m
> Remaining Estimate: 0h
>
> We generate correlated join when no correlate variable is present on the right side. However, this could be simplified to emit a normal join.
> Given:
> {code:java}
> final RelNode rel = builder
> .scan("EMP")
> .variable(v)
> .scan("DEPT")
> .join(JoinRelType.LEFT,
> builder.equals(builder.field(2, 0, "SAL"),
> builder.literal(1000)),
> ImmutableSet.of(v.get().id))
> .build();
> {code}
> Currently the following is emitted:
> {code}
> LogicalFilter(condition=[=($7, $8)])
> LogicalCorrelate(correlation=[$cor0], joinType=[left], requiredColumns=[{0}])
> LogicalTableScan(table=[[scott, EMP]])
> LogicalFilter(condition=[=($cor0.DEPTNO, $0)])
> LogicalTableScan(table=[[scott, DEPT]])
> {code}
> After the changes the following will be emitted:
> {code}
> LogicalJoin(condition=[=($7, $8)], joinType=[left])
> LogicalTableScan(table=[[scott, EMP]])
> LogicalTableScan(table=[[scott, DEPT]])
> {code}
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