Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp> writes:
> One thing I'm not sure about is: should we insist that a join can be
> pushed down only if the checkAsUser fields of the relevant RTEs are
> equal in the case where user mappings are meaningless to the FDW, like
> file_fdw?
If we add a mechanism to let us know that the FDW doesn't care, we could
relax the requirement for such cases. I don't have a strong opinion on
whether that's worthwhile. It'd depend in part on how many FDWs there
are that don't care, versus those that do; and I have no idea about that.
regards, tom lane