Re: PostgreSQL optimizer use seq scan instead of pkey index only scan (in queries with postgres_fdw)

[Tom Lane]

Jeff Janes <jeff.ja...@gmail.com> writes:
> It works the way you want in version 12, which is currently under
> development and should be released in 5 months or so.

Even in older versions, the OP would get a significantly smarter
plan after setting use_remote_estimate = on.  I think the core
issue here is that we won't generate remote parameterized paths
without that:

        /*
         * If we're not using remote estimates, stop here.  We have no way to
         * estimate whether any join clauses would be worth sending across, so
         * don't bother building parameterized paths.
         */
        if (!fpinfo->use_remote_estimate)
                return;

                        regards, tom lane