Re: array_agg() on a set larger than some arbitrary(?) limit causes runaway memory usage and eventually memory exhaustion

Hi Stephen,

Op maandag 21 oktober 2013 10:47:26 schreef Stephen Frost:
> > In production, I use it wherever it's _really_ needed, but mind
> > that the oom-killer in newer kernels is already selecting processes
> > a bit smarter than it used to. In the example I gave,
> > the correct child process was killed.

> The correct child being killed doesn't actually mean that it's a *good
> idea* to kill off PG child processes, in general, particularly in the
> way that the OOM killer goes about it (kill -9).  If it was possible to
> tune the OOM killer to use a different signal, which would allow PG to
> actually clean things up, it *might* be reasonable to allow it, but I
> still wouldn't recommend it.
>
> In production, for my part, proper memory accounting (and disabling of
> OOM) should *always* be used.

I did not describe this the way I should have, I meant to say that I do
exactly that: disable the OOM-killer _always_ in a production situation since
there it is _really_ needed.

I noticed on the development machine where I did the testing that the correct
child process was being killed, which used to not be the case.


Thanks for emphasizing this, though.




--

Best,




Frank.