On Wed, Jan 22, 2014 at 6:59 PM, Florian Weimer <fweimer@xxxxxxxxxx> wrote: > This happens with postgresql-server-9.3.2-2.fc20.x86_64. > > I track this down to a lower-than-usual setting of work_mem, to 1MB, after > the upgrade to 9.3. > > With work_mem set to 8MB, the query completes in a reasonable time frame, > with just a few thousand temporary files. EXPLAIN ANALYZE gives these > numbers: Were the settings different on old and new PostgreSQL versions? Do you have a query plan with the old version? Are the join columns indexed on both sides? Usually the planner prefers nested loops and merge joins with low work_mem, if the join columns are indexed. Increasing effective_cache_size and reducing random_page_cost to match your hardware may lead the planner to make better choices. Regards, Marti -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general