Chris Browne <cbbrowne@xxxxxxx> writes: > I once ran into the situation where Slony-I generated a query that > made the parser blow out (some sort of memory problem / running out of > stack space somewhere thing); it was just short of 640K long, and so > we figured that evidently it was wrong to conclude that "640K ought to > be enough for anybody." > Neil Conway was an observer; he was speculating that, with some > (possibly nontrivial) change to the parser, we should have been able > to cope with it. > The query consisted mostly of a NOT IN clause where the list had some > atrocious number of entries in it (all integers). FWIW, we do seem to have improved that as of 8.2. Assuming your entries were 6-or-so-digit integers, that would have been on the order of 80K entries, and we can manage it --- not amazingly fast, but it doesn't blow out the stack anymore. > (Aside: I wound up writing a "query compressor" (now in 1.2) which > would read that list and, if it was at all large, try to squeeze any > sets of consecutive integers into sets of "NOT BETWEEN" clauses. > Usually, the lists, of XIDs, were more or less consecutive, and > frequently, in the cases where the query got to MBs in size, there > would be sets of hundreds or even thousands of consecutive integers > such that we'd be left with a tiny query after this...) Probably still a win. regards, tom lane
