Re: [PERFORM] encourging bitmap AND

2010-12-25 Thread Marti Raudsepp
On Thu, Dec 23, 2010 at 22:52, Tom Lane wrote: > Ben writes: >> i have a schema similar to the following > >> create index foo_s_idx on foo using btree (s); >> create index foo_e_idx on foo using btree (e); > >> i want to do queries like > >> select * from foo where 150 between s and e; > > That

Re: [PERFORM] concurrent IO in postgres?

2010-12-25 Thread Mladen Gogala
Jeff Janes wrote: If the background writer cannot keep up, then the individual backends start doing writes as well, so it isn't really serialized.. Is there any parameter governing that behavior? Can you tell me where in the code (version 9.0.2) can I find that? Thanks. -- Mladen Gogala S

Re: [PERFORM] concurrent IO in postgres?

2010-12-25 Thread Jeff Janes
On Thu, Dec 23, 2010 at 11:46 AM, Przemek Wozniak wrote: > In one test I was running between 1 and 32 clients simultaneously > writing lots of data using copy binary. Are you by-passing WAL? If not, you are likely serializing on that. Not so much the writing, but the lock. > The problem is tha