Re: [PERFORM] postgresql-8.0.1 performance tuning

2005-06-01 Thread Mark Kirkwood
Cosimo Streppone wrote: # Config /etc/sysctl.conf: kernel.shmall = 786432000 kernel.shmmax = 786432000 I think you have a problem here. kernel.shmmax should *not* be set to an amount of RAM, but to maximum number of shared memory pages, which on a typical linux system is

Re: [PERFORM] postgresql-8.0.1 performance tuning

2005-06-01 Thread Mark Kirkwood
Cosimo Streppone wrote: Mark Kirkwood ha scritto: Cosimo Streppone wrote: # Config /etc/sysctl.conf: kernel.shmall = 786432000 kernel.shmmax = 786432000 I think you have a problem here. kernel.shmmax should *not* be set to an amount of RAM, but Sorry, I thought

[PERFORM] How to avoid database bloat

2005-06-01 Thread Mindaugas Riauba
Hello, Our database increases in size 2.5 times during the day. What to do to avoid this? Autovacuum running with quite aggressive settings, FSM settings are high enough. Database size should be more or less constant but it has high turnover rate (100+ insert/update/delete per second).

Re: [PERFORM] postgresql-8.0.1 performance tuning

2005-06-01 Thread Martin Fandel
Hi John, thank you very much for the answer :). I moved the pg_xlog to another partition and made a symlink to it. Know the database is much more faster than before. A sample select which was finished in 68seconds before, is now finished in 58seconds :). I will test the other changes today also

Re: [PERFORM] very large table

2005-06-01 Thread Simon Riggs
On Tue, 2005-05-31 at 11:37 +0200, Praveen Raja wrote: Im trying to move an existing solution from MySQL to PostgreSQL. As it is now the solution has 4 tables where data in inserted by an application. At regular intervals (10min) data from these tables is consolidated and moved to another

Re: [PERFORM] slow queries, possibly disk io

2005-06-01 Thread Simon Riggs
On Fri, 2005-05-27 at 07:52 -0500, Josh Close wrote: Setting shared buffers above something like 10-30% of memory is counter productive. What is the reason behind it being counter productive? If shared buffers are at 30%, should effective cache size be at 70%? How do those two relate?

[PERFORM] TIP 9: the planner will ignore... datatypes

2005-06-01 Thread Marc Mamin
TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match But INT2, INT4, INT8 and SERIAL are considered to be a unique datatype. Am I Right? Thanks, Marc -- Geschenkt: 3 Monate GMX ProMail gratis + 3 Ausgaben stern gratis ++

Re: [PERFORM] postgresql-8.0.1 performance tuning

2005-06-01 Thread Steinar H. Gunderson
On Wed, Jun 01, 2005 at 07:30:37AM +0200, Cosimo Streppone wrote: fsync = true false Just setting fsync=false without considering the implications is a _bad_ idea... /* Steinar */ -- Homepage: http://www.sesse.net/ ---(end of

Re: [PERFORM] postgresql-8.0.1 performance tuning

2005-06-01 Thread Martin Fandel
Yes, i think also that this setting should be enabled :). Am Mittwoch, den 01.06.2005, 11:57 +0200 schrieb Steinar H. Gunderson: On Wed, Jun 01, 2005 at 07:30:37AM +0200, Cosimo Streppone wrote: fsync = true false Just setting fsync=false without considering the

Re: [PERFORM] TIP 9: the planner will ignore... datatypes

2005-06-01 Thread Alvaro Herrera
On Wed, Jun 01, 2005 at 11:45:06AM +0200, Marc Mamin wrote: TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match But INT2, INT4, INT8 and SERIAL are considered to be a unique datatype. Am I Right? No, they weren't when

Re: [PERFORM] How to avoid database bloat

2005-06-01 Thread Tom Lane
Mindaugas Riauba [EMAIL PROTECTED] writes: Our database increases in size 2.5 times during the day. What to do to avoid this? Autovacuum running with quite aggressive settings, FSM settings are high enough. First thing I'd suggest is to get a more detailed idea of exactly what is bloating

Re: [PERFORM] Moving pg_xlog

2005-06-01 Thread Tom Lane
Keith Worthington [EMAIL PROTECTED] writes: I have been reading about increasing PostgreSQL performance by relocating the pg_xlog to a disk other than the one where the database resides. I have the following pg_xlogs on my system. /raid02/databases/pg_xlog /raid02/rhdb_databases/pg_xlog

Re: [PERFORM] Moving pg_xlog

2005-06-01 Thread Keith Worthington
On Wed, 01 Jun 2005 12:19:40 -0400, Tom Lane wrote Keith Worthington [EMAIL PROTECTED] writes: I have been reading about increasing PostgreSQL performance by relocating the pg_xlog to a disk other than the one where the database resides. I have the following pg_xlogs on my system.

Re: [PERFORM] Moving pg_xlog

2005-06-01 Thread Brad Nicholson
Keith Worthington wrote: On Wed, 01 Jun 2005 12:19:40 -0400, Tom Lane wrote Keith Worthington [EMAIL PROTECTED] writes: I have been reading about increasing PostgreSQL performance by relocating the pg_xlog to a disk other than the one where the database resides. I have the following

[PERFORM] Forcing use of specific index

2005-06-01 Thread Tobias Brox
Is it any way to attempt to force the planner to use some specific index while creating the plan? Other than eventually dropping all the other indices (which is obiously not a solution in production setting anyway)? I have one case where I have added 16 indices to a table, many of them beeing

[PERFORM] Adaptec/LSI/?? RAID

2005-06-01 Thread Stacy White
We're in the process of buying another Opteron server to run Postgres, and based on the suggestions in this list I've asked our IT director to get an LSI MegaRaid controller rather than one of the Adaptecs. But when we tried to place our order, our vendor (Penguin Computing) advised us: we find

Re: [PERFORM] Adaptec/LSI/?? RAID

2005-06-01 Thread Sven Willenberger
Stacy White presumably uttered the following on 06/01/05 23:42: We're in the process of buying another Opteron server to run Postgres, and based on the suggestions in this list I've asked our IT director to get an LSI MegaRaid controller rather than one of the Adaptecs. But when we tried to

Re: [PERFORM] Adaptec/LSI/?? RAID

2005-06-01 Thread William Yu
I've used LSI MegaRAIDs successfully in the following systems with both Redhat 9 and FC3 64bit. Arima HDAMA/8GB RAM Tyan S2850/4GB RAM Tyan S2881/4GB RAM I've previously stayed away from Adaptec because we used to run Solaris x86 and the driver was somewhat buggy. For Linux and FreeBSD, I'd