Great, thank you both for the info.
it's not
>> clear how they could change plans), and Bruce's answer to a comment
>> [2] suggests that this is not documented.
>
>> Is there any more info on this mechanism? Specifically, if one has
>> unused expression indexes (according to pg_stat_user_indexes), is
Maciek Sakrejda writes:
> Thanks, but I was asking specifically about _unused_ indexes
> (according to pg_stat_user_indexes). Bruce's blog post showed how they
> can still influence rowcount estimates, but can they do that (1) even
> if they don't end up being used by the query plan and (2) in a w
to pg_stat_user_indexes). Bruce's blog post showed how they
can still influence rowcount estimates, but can they do that (1) even
if they don't end up being used by the query plan and (2) in a way
that leads to a different plan?
Basically, if I have some unused expression indexes, is it safe to
drop them, or could they be used for planning optimizations even if
they are not used directly.
Thanks,
Maciek
and Bruce's answer to a comment
> [2] suggests that this is not documented.
> Is there any more info on this mechanism? Specifically, if one has
> unused expression indexes (according to pg_stat_user_indexes), is it
> safe to drop them? Or could they be providing statistics that
gests that this is not documented.
Is there any more info on this mechanism? Specifically, if one has
unused expression indexes (according to pg_stat_user_indexes), is it
safe to drop them? Or could they be providing statistics that
materially affect query planning even though the indexes themse
