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
Thank you.
Reading the code - probably the lowest hanging fruit is to make
'The current multiplier of 1000 * cpu_operator_cost' configurable in the future versions.
PS: it's always nice to see when my ad-hoc idea (about N*nrelations as cost planner estimate) is already implemented.
