Robert Haas <robertmh...@gmail.com> writes: > On Wed, Sep 19, 2012 at 10:30 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: >> To do what you want, I'd suggest wrapping the join into a sub-select >> with an "OFFSET 0" clause, which will serve as an optimization fence >> that prevents the random() call from being pushed down.
> You've repeatedly objected to complaints on pgsql-performance on the > grounds that WITH is an optimization fence. It seems awfully > inconsistent to turn around and say, oh, sometimes it's not a fence > after all. Huh? The join in question is not inside a WITH. If it were, that would work too, as noted by Merlin. 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