[CALCITE-3004] RexOver is incorrectly pushed down in ProjectSetOpTran…

[chunweilei]

…sposeRule and ProjectCorrelateTransposeRule (Chunwei Lei)

JIRA: https://issues.apache.org/jira/browse/CALCITE-3004

[chunweilei]

There is if..else.. in that I don't want to change the plan of some cases. For instance, current plan of

select ename,avg(empno) from 
(select * from emp as e1 union all select * from emp as e2)

is

LogicalAggregate(group=[{0}], EXPR$1=[AVG($1)])
  LogicalUnion(all=[true])
    LogicalProject(ENAME=[$1], EMPNO=[$0])
      LogicalTableScan(table=[[CATALOG, SALES, EMP]])
    LogicalProject(ENAME=[$1], EMPNO=[$0])
      LogicalTableScan(table=[[CATALOG, SALES, EMP]])

But if without if..else.., the plan becomes

LogicalAggregate(group=[{0}], EXPR$1=[AVG($1)])
  LogicalProject(ENAME=[$1], EMPNO=[$0])
    LogicalUnion(all=[true])
      LogicalProject(EMPNO=[$0], ENAME=[$1])
        LogicalTableScan(table=[[CATALOG, SALES, EMP]])
      LogicalProject(EMPNO=[$0], ENAME=[$1])
        LogicalTableScan(table=[[CATALOG, SALES, EMP]])

which seems redundant.

[chunweilei]

Note that testProjectCorrelateTranspose in RelOptRulesTest.xml is redundant[1][2].

[1] https://github.com/apache/calcite/blob/master/core/src/test/resources/org/apache/calcite/test/RelOptRulesTest.xml#L9226
[2] https://github.com/apache/calcite/blob/master/core/src/test/resources/org/apache/calcite/test/RelOptRulesTest.xml#L9253

[julianhyde]

Ah. Somehow there's a duplicate key in RelOptRulesTest.xml. Maybe it's a merge error, I don't know. Can someone add code to DiffRepository to make it fail when reading a .xml file if there are duplicate keys.

[chunweilei]

@julianhyde I would like to do it. : )

[chunweilei]

Opened an issue(CALCITE-3009) for it.

[chunweilei]

@julianhyde @zhztheplayer, could you please review the PR? Thanks a lot.

[chunweilei]

Updated for resolving conflicts.

[hsyuan]

+1