Re: Removing unneeded self joins

Hi All,

I just wanted to ask about the status and plans for this patch.
I can see it being stuck at “Waiting for Author” status in several commit tests.

I think this patch would be really beneficial for us as we heavily use views to structure out code.
Each view is responsible for providing some calculated values and they are joined in a query to retrieve the full set of information.

Not sure how the process works and how I could help (I am absolutely not capable of helping with coding I am afraid - but could sponsor a (small :) ) bounty to speed things up).

Thanks,
Michal

> On 16 Dec 2022, at 07:45, Andrey Lepikhov <a(dot)lepikhov(at)postgrespro(dot)ru> wrote:
>
> 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
> <v39-0001-Remove-self-joins.patch>