Sadly it doesn't help to disable indexscan. The plan : https://explain.dalibo.com/plan/3b3gfce5b29c3hh4
De : Peter Geoghegan <pg@xxxxxxx>
Envoyé : lundi 12 juin 2023 22:34:50
À : benoit
Cc : pgsql-performance@xxxxxxxxxxxxxxxxxxxx
Objet : Re: Forced to use UNION ALL when having multiple ANY operators and ORDER BY LIMIT
Envoyé : lundi 12 juin 2023 22:34:50
À : benoit
Cc : pgsql-performance@xxxxxxxxxxxxxxxxxxxx
Objet : Re: Forced to use UNION ALL when having multiple ANY operators and ORDER BY LIMIT
On Mon, Jun 12, 2023 at 1:17 PM benoit <benoit@xxxxxxxxxxxxxxx> wrote:
> Is there a misusage of my indexes?
>
> Is there a limitation when using ANY or IN operators and ordered LIMIT behind?
It's complicated. Do you find that you get satisfactory performance if
you force a bitmap index scan? In other words, what is the effect of
"set enable_indexscan = off" on your original query? Does that speed
up execution at all? (I think that this approach ought to produce a
plan that uses a bitmap index scan in place of the index scan, without
changing anything else.)
--
Peter Geoghegan
> Is there a misusage of my indexes?
>
> Is there a limitation when using ANY or IN operators and ordered LIMIT behind?
It's complicated. Do you find that you get satisfactory performance if
you force a bitmap index scan? In other words, what is the effect of
"set enable_indexscan = off" on your original query? Does that speed
up execution at all? (I think that this approach ought to produce a
plan that uses a bitmap index scan in place of the index scan, without
changing anything else.)
--
Peter Geoghegan
