On Thu, Sep 17, 2009 at 1:31 PM, Bill Moran <wmoran@xxxxxxxxxxxxxxxxx> wrote: > In response to Scott Marlowe <scott.marlowe@xxxxxxxxx>: > >> On Thu, Sep 17, 2009 at 12:56 PM, Alan McKay <alan.mckay@xxxxxxxxx> wrote: >> > Is there any way to limit a query to a certain amount of RAM and / or >> > certain runtime? >> > >> > i.e. automatically kill it if it exceeds either boundary? >> > >> > We've finally narrowed down our system crashes and have a smoking gun, >> > but no way to fix it in the immediate term. This sort of limit would >> > really help us. >> >> Generally speaking work_mem limits ram used. What are your >> non-default postgresql.conf settings? > > work_mem limits memory usage _per_sort_. > > A big query can easily have many sorts. Each sort will be limited to > work_mem memory usage, but the total could be much higher. > > The only way I can think is to set a per-process limit in the OS and allow > the OS to kill a process when it gets out of hand. Not ideal, though. True, but with a work_mem of 2M, I can't imagine having enough sorting going on to need 4G of ram. (2000 sorts? That's a lot) I'm betting the OP was looking at top and misunderstanding what the numbers mean, which is pretty common really. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
