[
https://issues.apache.org/jira/browse/CALCITE-7931?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18142621#comment-18142621
]
Mihai Budiu commented on CALCITE-7931:
--------------------------------------
This fix overlaps with CALCITE-7929 so I will wait for that one to be merged
before submitting a PR.
> RelDecorrelator gives wrong results for a correlated sub-query with GROUPING
> SETS that contain a constant key
> -------------------------------------------------------------------------------------------------------------
>
> Key: CALCITE-7931
> URL: https://issues.apache.org/jira/browse/CALCITE-7931
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.42.0
> Environment: Related to CALCITE-7929 CALCITE-7930
> Reporter: Mihai Budiu
> Priority: Minor
>
> A correlated sub-query whose GROUPING SETS, ROLLUP or CUBE contain a constant
> key returns wrong results after RelDecorrelator, with no error.
> {code:java}
> !use scott
> !set outputformat mysql
> !set expand false
> # Each department has 2 groups, ('a') and ().
> # DEPT 40 is left out because of CALCITE-7930.
> select deptno,
> (select count(*) from
> (select count(*) as n from emp where emp.deptno = dept.deptno
> group by grouping sets (('a'), ())) as t) as g
> from dept
> where deptno < 40;
> +--------+---+
> | DEPTNO | G |
> +--------+---+
> | 10 | 2 |
> | 20 | 2 |
> | 30 | 2 |
> +--------+---+
> (3 rows)
> !ok
> {code}
> PostgreSQL 14 returns the rows above (with 'a'::text, because PostgreSQL
> rejects a string constant in GROUP BY). RelDecorrelator returns G = 1 for
> each department, with expand=false and with expand=true.
> TopDownGeneralDecorrelator returns the correct result.
> Number of groups for each of DEPT 10, 20 and 30:
> ||GROUP BY||Correct (PostgreSQL)||RelDecorrelator||
> |GROUPING SETS (('a'), ())|2|1|
> |CUBE('a')|2|1|
> |ROLLUP('a', job)|5|0|
> |ROLLUP(job, 'a')|7|3|
> |GROUPING SETS (('a', job), (job))|6|0|
> |GROUPING SETS (('a', job), ('a'))|4|0|
>
--
This message was sent by Atlassian Jira
(v10.3.26#10030026)
