Re: [PERFORM] Recommended File System Configuration

2004-05-03 Thread Chris Browne
[EMAIL PROTECTED] (James Thornton) writes: Back in 2001, there was a lengthy thread on the PG Hackers list about PG and journaling file systems (http://archives.postgresql.org/pgsql-hackers/2001-05/msg00017.php), but there was no decisive conclusion regarding what FS to use. At the time the

[PERFORM] cache table

2004-05-03 Thread Joseph Shraibman
I have a big table with some int fields. I frequently need to do queries like: SELECT if2, count(*) FROM table WHERE if1 = 20 GROUP BY if2; The problem is that this is slow and frequently requires a seqscan. I'd like to cache the results in a second table and update the counts with triggers,

Re: [PERFORM] linux distro for better pg performance

2004-05-03 Thread James Thornton
Joseph Shraibman wrote: Is raid 5 much faster than raid 10? On a 4 disk array with 3 data disks and 1 parity disk, you have to write 4/3rds the original data, while on raid 10 you have to write 2 times the original data, so logically raid 5 should be faster. RAID 5 will give you more capacity,

Re: [PERFORM] linux distro for better pg performance

2004-05-03 Thread Alan Stange
Joseph Shraibman wrote: J. Andrew Rogers wrote: Do these features make a difference? Far more than you would imagine. On one postgres server I just upgraded, we went from a 3Ware 8x7200-RPM RAID-10 configuration to an LSI 320-2 SCSI 3x10k RAID-5, with 256M Is raid 5 much faster than raid 10?

[PERFORM] INSERT RULE

2004-05-03 Thread Pailloncy Jean-Gérard
Hi, I test a configuration where one table is divided in 256 sub-table. And I use a RULE to offer a single view to the data. For INSERT I have create 256 rules like: CREATE RULE ndicti_000 AS ON INSERT TO ndict WHERE (NEW.word_id 255) = 000 DO INSTEAD INSERT INTO ndict_000 VALUES(

Re: [PERFORM] Fwd: FreeBSD, PostgreSQL, semwait and sbwait!

2004-05-03 Thread Pailloncy Jean-Gérard
Hello, We're having a substantial problem with our FreeBSD 5.2 database server running PostgreSQL - it's getting a lot of traffic (figure about 3,000 queries per second), but queries are slow, and it's seemingly waiting on other things than CPU time Could this be a 5.2 performance issue ? In