Re: inefficient/wrong plan cache mode selection for queries with partitioned tables (postgresql 17)

Maxim Boguk <maxim.boguk@gmail.com> writes:
> And the problem is that the cost of a custom plan ignores the cost of
> planning itself (which is like 2x orders of magnitude worse than the cost
> of real time partition pruning of a generic plan).

False.  The estimate is evidently pretty wrong, but it's not that
there is no consideration at all.  See around line 1370 in
src/backend/utils/cache/plancache.c.

            regards, tom lane