=?UTF-8?Q?Mladen_Marinovi=C4=87?= <mladen.marinovic@kset.org> writes:
> After a couple of hours of trying different stuff, set enable_mergejoin =
> off made the planning time look better: Planning time: 0.322 ms
> Any ideas why this helps?
Hmm, possibly because it's reducing the number of calls to
get_actual_variable_range. Do you have an indexed column,
with a lot of recently-dead entries at the end of its range,
that is a join key in the slow query? If so, you might be
hitting the problem that was fixed (not for 9.6) here:
https://git.postgresql.org/gitweb/?p=postgresql.git&a=commitdiff&h=3ca930fc3
regards, tom lane