Alvaro Herrera <alvherre@commandprompt.com> writes:
> I don't very much like the wildcard idea; but I don't think it's
> unreasonable to refuse to provide a file size. If the owning backend
> has still got part of the table in local buffers, you'll get a
> misleading answer, so perhaps it's best to not give an answer at all.
FWIW, that's not the case, anymore than it is for blocks in shared
buffer cache for regular rels. smgrextend() results in an observable
extension of the file EOF immediately, whether or not you can see
up-to-date data for those pages.
Now people have often complained about the extra I/O involved in that,
and it'd be nice to have a solution, but it's not clear to me that
fixing it would be harder for temprels than regular rels.
regards, tom lane