Robert Haas <robertmhaas@xxxxxxxxx> writes: > On Mon, May 13, 2013 at 4:14 PM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: >> You know, of course, that the join size estimate isn't arrived at that >> way. Still, this point does make it seem more like a planner bug and >> less like bad input stats. It would be nice to see a self-contained >> example ... > Yeah, I remember there have been examples like this that have come up > before. Unfortunately, I haven't fully grokked what's actually going > on here that allows this kind of thing to happen. Refresh my memory > on where the relevant code is? The point is that we estimate the size of a joinrel independently of any particular input paths for it, and indeed before we've built any such paths. So this seems like a bug somewhere in selectivity estimation, but I'm not prepared to speculate as to just where. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
