On 5/12/25 13:49, Maxim Boguk wrote:
I suspect this situation should be quite common with queries over
partitioned tables (where planning time is usually quite a high).
Any suggestions what could be done there outside of using
force_generic_plan for a particular db user (which will kill performance
in other queries for sure)?
Thanks for this puzzle!
I suppose, in case generic planning is much faster than custom one,
there are two candidates exist:
1. Touching the index during planning causes too much overhead - see
get_actual_variable_range
2. You have a massive default_statistics_target for a table involved.
So, to clarify the problem, may you provide EXPLAIN (without analyze)
with BUFFERS ON ?
Also, could you provide extra information on the statistics involved?
For each column (I think created_at is the most important one), show the
size of MCV and histogram arrays.
--
regards, Andrei Lepikhov
