On Fri, Nov 29, 2013 at 3:07 PM, Jan Michel <Jan(at)mueschelsoft(dot)de> 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.