Re: [PERFORM] Redundant sub query triggers slow nested loop left join

2007-04-28 Thread henk de wit
Perhaps one other interesting observation; when I earlier removed the status check for which the rows got so wrongly estimated, the query got dramatically faster. However, once I also remove all redundant checks the query gets slower again. This is the query with both status and redundant chec

Re: [PERFORM] Very specific server situation

2007-04-28 Thread Mauro N. Infantino
Tom, Thank you very much for your suggestions. > -Original Message- > From: Tom Lane [mailto:[EMAIL PROTECTED] > > Have you checked to make sure the query plans are reasonable? I've attached the main query and its explain plan. I can't find a way to improve it. Does it make any diff

Re: [PERFORM] Feature Request --- was: PostgreSQL Performance Tuning

2007-04-28 Thread Carlos Moreno
Harald Armin Massa wrote: Carlos, about your feature proposal: as I learned, nearly all Perfomance.Configuration can be done by editing the .INI file and making the Postmaster re-read it. So, WHY at all should those parameters be guessed at the installation of the database? Would'nt it be a

Re: [PERFORM] Usage up to 50% CPU

2007-04-28 Thread Andres Retzlaff
On Fri, Apr 27, 2007 at 07:23:41PM +0930, Shane Ambler wrote: I would think that as you are sitting and watching the cpu usage, your query would seem to taking a while to run, leading me to wonder if you are getting a full table scan that is causing pg to wait for disk response? If so, you pro

Re: [PERFORM] Feature Request --- was: PostgreSQL Performance Tuning

2007-04-28 Thread Harald Armin Massa
Jonah, Um, shared_buffers is one of the most important initial parameters to set and it most certainly cannot be set after startup. Not after startup, correct. But after installation. It is possible to change PostgreSQL.conf (not ini, to much windows on my side, sorry) and restart postmaster.

Re: [PERFORM] Feature Request --- was: PostgreSQL Performance Tuning

2007-04-28 Thread Jonah H. Harris
On 4/28/07, Harald Armin Massa <[EMAIL PROTECTED]> wrote: about your feature proposal: as I learned, nearly all Perfomance.Configuration can be done by editing the .INI file and making the Postmaster re-read it. Um, shared_buffers is one of the most important initial parameters to set and it mo

Re: [PERFORM] Redundant sub query triggers slow nested loop left join

2007-04-28 Thread henk de wit
Well, that's darn odd. It should not be getting that so far wrong. I've been puzzling on this for over a week now, but can't seem to find a solution. Would you have some more hints of what I could possibly try next? As far as I can see, the mentioned status column is just a simple column. Or

Re: [PERFORM] Feature Request --- was: PostgreSQL Performance Tuning

2007-04-28 Thread Harald Armin Massa
Carlos, about your feature proposal: as I learned, nearly all Perfomance.Configuration can be done by editing the .INI file and making the Postmaster re-read it. So, WHY at all should those parameters be guessed at the installation of the database? Would'nt it be a saver point of time to have so