On Fri, Nov 29, 2013 at 3:07 PM, Jan Michel <Jan@xxxxxxxxxxxxxxx> wrote: > Dear all, > I have a quite strange problem running an extensive query on geo data > checking for crossing ways. I don't know if this is a postgres or postgis > problem, but I hope you can help. Running one thread is no problem, it > finishes within 10-15 minutes. Run two of those queries in parallel and > they will not finish within 24 hours. It is definitely not a caching or I/O > problem. What does your IO subsystem look like when you're running the query both once and twice? iostat, vmstat, iotop etc area ll useful here. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance