2009/9/25 Jeff Janes <jeff.janes@xxxxxxxxx>: > 2009/9/22 Grzegorz Jaśkiewicz <gryzman@xxxxxxxxx>: >> On Tue, Sep 22, 2009 at 1:46 PM, Alan McKay <alan.mckay@xxxxxxxxx> wrote: >>>> Best practice to avoid that, is to bump the work_mem temporarily >>>> before the query, and than lower it again, lowers the chance of memory >>>> exhaustion. >>> >>> Interesting - I can do that dynamically? >> >> you can do set work_mem=128M; select 1; set work_mem=64M; >> >> etc, in one query. > > But if all backends are running this one query at the same time, it > won't help because they will all bump up their limits at the same > time. If they are all running different queries, and just one of them > really gets a big benefit from the extra memory, but the rest just use > it because they think they have it even though it is only a small > benefit, then bumping up just for the query that gets a big > improvement could work. This is, I think, a possible area for future optimizer work, but the right design is far from clear. ...Robert -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
