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Posted to issues@calcite.apache.org by "James Starr (Jira)" <ji...@apache.org> on 2021/06/25 19:43:00 UTC
[jira] [Updated] (CALCITE-4668) RelBuilder.join should only emit a
correlate when a correlate variable exists
[ https://issues.apache.org/jira/browse/CALCITE-4668?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
James Starr updated CALCITE-4668:
---------------------------------
Description:
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}
was:
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}
> RelBuilder.join should only emit a correlate when a correlate variable exists
> -----------------------------------------------------------------------------
>
> Key: CALCITE-4668
> URL: https://issues.apache.org/jira/browse/CALCITE-4668
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Reporter: James Starr
> Priority: Major
>
> 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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