[PERFORM] database bloat,non removovable rows, slow query etc...

2006-09-01 Thread Matteo Sgalaberni
Hi, probably this is a very frequenfly question... I read archivies of this list but I didn't found a finally solution for this aspect. I'll explain my situation. PSQL version 8.1.3 configuration of fsm,etcc default autovacuum and statistics activated 22 daemons that have a persistent connection

Re: [PERFORM] database bloat,non removovable rows, slow query etc...

2006-09-01 Thread Tom Lane
Matteo Sgalaberni <[EMAIL PROTECTED]> writes: > 22 daemons that have a persistent connection to this database(all > connection are in "idle"(no transaction opened). You may think that, but you are wrong. > INFO: "cliente": found 0 removable, 29931 nonremovable row versions in 559 > pages > DETA

Re: [PERFORM] database bloat,non removovable rows, slow query etc...

2006-09-01 Thread Patrick Hatcher
Are there open transactions on the table in question? We had the same issue. A 100K row table was so bloated that the system thought there was 1M rows. We had many transaction that we noticed in TOP, but since we could not track down which process or user was holding the table we had to restart

Re: [PERFORM] database bloat,non removovable rows, slow query etc...

2006-09-01 Thread Markus Schaber
Hi, Tom and Matteo, Tom Lane wrote: > Matteo Sgalaberni <[EMAIL PROTECTED]> writes: >> 22 daemons that have a persistent connection to this database(all >> connection are in "idle"(no transaction opened). > > You may think that, but you are wrong. > >> INFO: "cliente": found 0 removable, 29931

[PERFORM] increasing shared buffers: how much should be removed from OS filesystem cache?

2006-09-01 Thread Guillaume Cottenceau
Hi, I've been looking at the results from the pg_statio* tables, to view the impact of increasing the shared buffers to increase performance. As expected, increasing from the default by a factor of 10~20 moves table/index disk blocks reads to cache hits, but the overall service time of my test pa

Re: [PERFORM] database bloat,non removovable rows, slow query etc...

2006-09-01 Thread Matteo Sgalaberni
On Fri, Sep 01, 2006 at 10:43:30AM -0400, Tom Lane wrote: > Matteo Sgalaberni <[EMAIL PROTECTED]> writes: > > 22 daemons that have a persistent connection to this database(all > > connection are in "idle"(no transaction opened). > > You may think that, but you are wrong. Ok. I stopped all clients.

Re: [PERFORM] database bloat,non removovable rows, slow query etc...

2006-09-01 Thread Tom Lane
Matteo Sgalaberni <[EMAIL PROTECTED]> writes: > Ok. I stopped all clients. No connections to this database. When you say "this database", do you mean the whole postmaster cluster, or just the one database? Open transactions in other databases of the same cluster can be a problem.

Re: [PERFORM] increasing shared buffers: how much should be removed from OS filesystem cache?

2006-09-01 Thread Merlin Moncure
On 01 Sep 2006 19:00:52 +0200, Guillaume Cottenceau <[EMAIL PROTECTED]> wrote: Hi, I've been looking at the results from the pg_statio* tables, to view the impact of increasing the shared buffers to increase performance. I think 'shared buffers' is one of the most overrated settings from a pe

Re: [PERFORM] database bloat,non removovable rows, slow query

2006-09-01 Thread Scott Marlowe
On Fri, 2006-09-01 at 12:28, Matteo Sgalaberni wrote: > On Fri, Sep 01, 2006 at 10:43:30AM -0400, Tom Lane wrote: > > Matteo Sgalaberni <[EMAIL PROTECTED]> writes: > > > 22 daemons that have a persistent connection to this database(all > > > connection are in "idle"(no transaction opened). > > > >

Re: [PERFORM] increasing shared buffers: how much should be removed from OS filesystem cache?

2006-09-01 Thread Dave Cramer
Guillaume 1G is really not a significant amount of memory these days, That said 6-10% of available memory should be given to an 8.0 or older version of postgresql Newer versions work better around 25% I'm not sure what you mean by mechanically removed from effective_cache effective cache i

Re: [PERFORM] increasing shared buffers: how much should be removed from OS filesystem cache?

2006-09-01 Thread Dave Cramer
On 1-Sep-06, at 3:49 PM, Merlin Moncure wrote: On 01 Sep 2006 19:00:52 +0200, Guillaume Cottenceau <[EMAIL PROTECTED]> wrote: Hi, I've been looking at the results from the pg_statio* tables, to view the impact of increasing the shared buffers to increase performance. I think 'shared buffer

Re: [PERFORM] increasing shared buffers: how much should be removed

2006-09-01 Thread Joshua D. Drake
I think 'shared buffers' is one of the most overrated settings from a performance standpoint. however you must ensure there is enough for things the server does besides caching. It used to be a bigger deal than it is in modern versionf of postgresql modern operating systems. Previous to 8.1 I