Juan, On 4/5/06 1:54 PM, "Juan Casero (FL FLC)" <Juan.Casero@xxxxxxxxxxxxxx> wrote: > I am not sure about this. I mean I have postgresql 8.1.3 running on my > Windows XP P4 HT laptop that I use for testing my webapps. When I hit > this pgsql on this laptop with a large query I can see the load spike up > really high on both of my virtual processors. Whatever, pgsql is doing > it looks like both cpu's are being used indepently. The usage curve is > not identical on both of them that makes me think that parts of the > server are multithreaded. Admittedly I am not familiar with the source > code fo postgresql so I was hoping maybe one of the developers who is > could definitely answer this question. There's no part of the Postgres backend that is threaded or multi-processed. A reasonable explanation for your windows experience is that your web server or the psql client may be taking some CPU cycles while the backend is processing your query. Also, depending on how the CPU load is reported, if the OS is doing prefetching of I/O, it might show up as load. - Luke