Hello,
This topic was discussed in
https://issues.apache.org/jira/browse/CALCITE-1584.
I am sure if Calcite does it, but in another SQL parser/analyzer
implementation I have saw, each logical plan has a top attribute about
final output column names, so even nodes might be merged/removed, at least
there are still output column names that we can get.
-Rui
On Wed, May 27, 2020 at 5:38 AM 董 一峰 <donga...@outlook.com> wrote:
> Hello everyone,
>
> When we run the following test case:
> SQL:
> WITH T_CTE (i1_cte, i2_cte) AS (
> SELECT
> i1,
> d3
> FROM
> t1
> )
> SELECT
> *
> FROM
> t2
> JOIN T_CTE ON (t2.i1 = T_CTE.i1_cte)
>
>
> Logical Plan(After ProjectRemoveRule):
> LogicalJoin(condition=[=($0, $14)], joinType=[inner])
> :- LogicalTableScan(table=[[default, db1, t2]])
> +- LogicalCalc(expr#0..13=[{inputs}], i1=[$t0], d3=[$t2])
> +- LogicalTableScan(table=[[default, db1, t1]])
>
>
> We wish the output column name contain i1_cte, i2_cte, but calcite just
> drop it.
> After analysisinp the calcite code, we found the rule named
> ProjectRemoveRule, it will remove the project if project and its input has
> same size and type, but it confused me, why this rule dose not consider the
> field name when remove project?
>
> Best Regards
> Axis
>
>
