Re: [sqlsmith] Planner crash on foreign table join

Andrew Gierth <andrew(at)tao11(dot)riddles(dot)org(dot)uk> writes:
> "Andreas" == Andreas Seltenreich <seltenreich(at)gmx(dot)de> writes:
> Andreas> testing master at f0e44021df with a loopback postgres_fdw
> Andreas> installed, I see lots of crashes on queries joining foreign
> Andreas> tables with various expressions. Below is a reduced recipe
> Andreas> for the regression database and a backtrace.

> Commit ac2b095088 assumes that clauselist_selectivity is being passed a
> list of RelOptInfo, but postgres_fdw is passing it a list of bare
> clauses. One of them is wrong :-)

It's a bit scary that apparently none of the committed regression tests
caught that.

More generally, I think the convention up to now has been that
clauselist_selectivity would work on either RestrictInfos or bare boolean
clauses, caching its results in the former case but succeeding anyway.
If we're to standardize on only one of those behaviors it should certainly
be the former, but I think postgres_fdw is probably not the only code that
will be broken if we remove the option for the latter.

regards, tom lane