Re: Large join runs out of memory in 8.1

Joe Sunday <sunday@csh.rit.edu> writes:
> It'll take me a while to come up with a dataset I can distribute that
> causes it. My first pass at fake random data didn't seem to trigger it,
> and I can't divulge the real data.

> I can poke with gdb, is there a guide for what to look for somewhere?

It's not the easiest sort of problem to debug :-( ...

What I'd try is first letting the problem case run for a bit, then
stopping it with gdb and dumping out a few Kb of the frontmost memory
block in the ExecutorState context.  Sometimes, looking at the data
that's being leaked is enough to give you a clue.  If not, try setting a
breakpoint at AllocSetAlloc and trying to see where the majority of
calls are coming from.  It'll be tedious ...

If you get bored, I'm willing to sign an NDA covering the data involved.

            regards, tom lane