Robert Haas <robertmh...@gmail.com> writes: > On Mon, Aug 24, 2009 at 9:31 PM, Josh Berkus<j...@agliodbs.com> wrote: >> What I don't get is why this is such a usability issue. Subqueries in >> DELETE FROM work perfectly well, and provide more flexibility than most >> users know what to do with.
> It's both a usability issue and a performance issue. On the usability front: if we were to take the position Josh advocates, we should never have added FROM/USING to UPDATE/DELETE at all ... but since we did, I think we should try to make it as flexible as the corresponding feature in other DBMSes. On the performance front: yeah, you can recast most joins as subqueries, but you tend to end up with the equivalent of a nestloop plan. Works okay for small numbers of rows, scales horribly. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers