On Wednesday 08 July 2009 23:46:02 Tom Lane wrote: > "Kevin Grittner" <kevin.gritt...@wicourts.gov> writes: > > For a moment it seemed logical to suggest a session GUC for the seed, > > so if you got a bad plan you could keep rolling the dice until you got > > one you liked; but my right-brain kept sending shivers down my spine > > to suggest just how uncomfortable it was with that idea.... > > If memory serves, we actually had exactly that at some point. But I > think the reason it got taken out was that it interfered with the > behavior of the random() function for everything else. We'd have to > give GEQO its own private random number generator. All of GEQOs usage of random() seems to be concentrated to geqo_random.h - so it would be a small change. I will happily tackle that. If only to narrow down in which cases geqo fails to plan - a behaviour we have seen at times at a bit more crazy queries.
The only question I have is, whether random_r or similar is available on enough platforms... Has anybody an idea about this? On most unixoid system one could just wrap erand48() if random_r is not available. Windows? Andres -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
