Magnus Hagander <magnus@xxxxxxxxxxxx> writes: > Apparantly there is a bug lurking somewhere in pgwin32_select(). Because > if I put a #undef select right before the select in pgstat.c, the > regression tests pass. > I guess the bug is shown because with row level stats we simply have > more data to process. And it appears only to happen on UDP sockets from > what I can tell. Hmm ... if this theory is correct, then statistics collection has never worked at all on Windows, at least not under more than the most marginal load; and hence neither has autovacuum. Does that conclusion agree with reality? You'd think we'd have heard a whole lot of complaints about it, not just Jeremy's; and I don't remember it being a sore point. (But then again I just woke up.) What seems somewhat more likely is that we broke pgwin32_select recently, in which case we oughta find out why. Or else remove it entirely (does your patch make that possible?). Keep in mind also that we have seen the stats-test failure on non-Windows machines, so we still need to explain that ... regards, tom lane