Re: Removing unneeded self joins

On 12/6/22 23:46, Andres Freund wrote:
> This doesn't pass the main regression tests due to a plan difference.
> https://cirrus-ci.com/task/5537518245380096
> https://api.cirrus-ci.com/v1/artifact/task/5537518245380096/testrun/build/testrun/regress/regress/regression.diffs
> 
> diff -U3 /tmp/cirrus-ci-build/src/test/regress/expected/join.out
/tmp/cirrus-ci-build/build/testrun/regress/regress/results/join.out
> --- /tmp/cirrus-ci-build/src/test/regress/expected/join.out    2022-12-05 19:11:52.453920838 +0000
> +++ /tmp/cirrus-ci-build/build/testrun/regress/regress/results/join.out    2022-12-05 19:15:21.864183651 +0000
> @@ -5806,7 +5806,7 @@
>    Nested Loop
>      Join Filter: (sj_t3.id = sj_t1.id)
>      ->  Nested Loop
> -         Join Filter: (sj_t3.id = sj_t2.id)
> +         Join Filter: (sj_t2.id = sj_t3.id)
>            ->  Nested Loop Semi Join
>                  ->  Nested Loop
>                        ->  HashAggregate
This change in the test behaviour is induced by the a5fc4641
"Avoid making commutatively-duplicate clauses in EquivalenceClasses."
Nothing special, as I see. Attached patch fixes this.

-- 
Regards
Andrey Lepikhov
Postgres Professional