Re: Memoize ANTI and SEMI JOIN inner - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Memoize ANTI and SEMI JOIN inner
Date
Msg-id stm4qkkcm2cr45kgkbgudaya5a3vvm3elgkvuopp5rmmw2uodl@lnhexcxa6olh
Whole thread Raw
In response to Re: Memoize ANTI and SEMI JOIN inner  (Richard Guo <guofenglinux@gmail.com>)
Responses Re: Memoize ANTI and SEMI JOIN inner
List pgsql-hackers
Hi,

On 2025-04-10 19:36:14 +0900, Richard Guo wrote:
> On Wed, Apr 9, 2025 at 6:18 PM David Rowley <dgrowleyml@gmail.com> wrote:
> > On Wed, 9 Apr 2025 at 18:48, Richard Guo <guofenglinux@gmail.com> wrote:
> > > Perhaps we could spend some planner cycles proving inner_unique for
> > > anti joins, so that Memoize nodes can be considered for them?
>
> > Worth a try. It should be pretty easy to enable, as far as I can see.
> > It might just be a case of shuffling the cases around in the switch
> > statement in add_paths_to_joinrel().
>
> Right.  Here is a patch for that.

This is failing on CI:
https://cirrus-ci.com/github/postgresql-cfbot/postgresql/cf%2F5636
https://api.cirrus-ci.com/v1/artifact/task/5411026402803712/testrun/build-32/testrun/regress/regress/regression.diffs

diff -U3 /tmp/cirrus-ci-build/src/test/regress/expected/memoize.out
/tmp/cirrus-ci-build/build-32/testrun/regress/regress/results/memoize.out
--- /tmp/cirrus-ci-build/src/test/regress/expected/memoize.out    2025-04-12 11:24:10.866868945 +0000
+++ /tmp/cirrus-ci-build/build-32/testrun/regress/regress/results/memoize.out    2025-04-12 11:32:44.454864476 +0000
@@ -525,7 +525,7 @@
                      ->  Unique (actual rows=2.67 loops=N)
                            ->  Sort (actual rows=67.33 loops=N)
                                  Sort Key: t2_1.a
-                                 Sort Method: quicksort  Memory: 27kB
+                                 Sort Method: quicksort  Memory: 18kB
                                  ->  Seq Scan on tab_anti t2_1 (actual rows=100.00 loops=N)
 (15 rows)


There shouldn't be Memory mentioned in tests added to the tree.

Greetings,

Andres



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