On 2019-05-20 23:30, Tom Lane wrote:
> Hmm ... given that pg_get_publication_tables() shouldn't return any
> duplicate OIDs, it does seem unnecessarily inefficient to put it in
> an IN-subselect condition. Peter, is there a reason why this isn't
> a straight lateral join? I get a much saner-looking plan from
>
> FROM pg_publication P, pg_class C
> - JOIN pg_namespace N ON (N.oid = C.relnamespace)
> - WHERE C.oid IN (SELECT relid FROM pg_get_publication_tables(P.pubname));
> + JOIN pg_namespace N ON (N.oid = C.relnamespace),
> + LATERAL pg_get_publication_tables(P.pubname)
> + WHERE C.oid = pg_get_publication_tables.relid;
No reason I think, just didn't quite manage to recognize the possibility
of using LATERAL at the time.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
