Re: [PERFORM] Caching of Queries

2004-12-23 Thread Pierre-Frédéric Caillaud
I've looked at PREPARE, but apparently it only lasts per-session - that's worthless in our case (web based service, one connection per data-requiring connection). You don't use persistent connections ??? Your problem might simply be the connection time overhead (also including a fe

Re: [PERFORM] Using LIMIT changes index used by planner

2004-12-23 Thread Pierre-Frédéric Caillaud
On Mon, 13 Dec 2004 17:43:07 -0500, Tom Lane <[EMAIL PROTECTED]> wrote: Sven Willenberger <[EMAIL PROTECTED]> writes: explain analyze select storelocation,order_number from custacct where referrer = 1365 and orderdate between '2004-12-07' and '2004-12-07 12:00:00' order by custacctid limit 10;

Re: [PERFORM] LIMIT causes SEQSCAN in subselect

2004-12-23 Thread Pierre-Frédéric Caillaud
The fact that the estimator knows that the LIMIT is pointless because there are less rows in the subselect than the LIMIT will return is not something we want to count on; sometimes the estimator has innaccurate information. The UNIQUE index makes this more certain, except that I'm not sure

Re: [PERFORM] Memory leak tsearch2 VACUUM FULL VERBOSE ANALYZE

2004-12-23 Thread Tom Lane
Pailloncy Jean-Gerard <[EMAIL PROTECTED]> writes: > I think I have a test case for 7.4.2 Try the attached patch. It looked to me like there were some smaller leaks going on during COPY and CREATE INDEX, which I will look into later --- but this seems to be the problem for VACUUM FULL.

Re: [PERFORM] Some Performance Advice Needed

2004-12-23 Thread William Yu
IDE disks lie about write completion (This can be disabled on some drives) whereas SCSI drives wait for the data to actually be written before they report success. It is quite easy to corrupt a PG (Or most any db really) on an IDE drive. Check the archives for more info. Do we have any real i

Re: [PERFORM] Some Performance Advice Needed

2004-12-23 Thread Joshua D. Drake
Jeff wrote: On Dec 23, 2004, at 9:27 AM, Alex wrote: Running hdparm reported A) 920mb/s (SCSI 10k) B) 270mb/s (SCSI 10k) C) 1750mb/s (IDE 7.2k) IDE disks lie about write completion (This can be disabled on some drives) whereas SCSI drives wait for the data to actually be written before th

Re: [PERFORM] Some Performance Advice Needed

2004-12-23 Thread William Yu
Alex wrote: Hi, i recently run pgbench against different servers and got some results I dont quite understand. A) EV1: Dual Xenon, 2GHz, 1GB Memory, SCSI 10Krpm, RHE3 B) Dual Pentium3 1.4ghz (Blade), SCSI Disk 10Krmp, 1GB Memory, Redhat 8 C) P4 3.2GHz, IDE 7.2Krpm, 1GBMem, Fedora Core2 > Runnig P

Re: [PERFORM] Some Performance Advice Needed

2004-12-23 Thread Jeff
On Dec 23, 2004, at 9:27 AM, Alex wrote: Running hdparm reported A) 920mb/s (SCSI 10k) B) 270mb/s (SCSI 10k) C) 1750mb/s (IDE 7.2k) IDE disks lie about write completion (This can be disabled on some drives) whereas SCSI drives wait for the data to actually be written before they report su

[PERFORM] Some Performance Advice Needed

2004-12-23 Thread Alex
Hi, i recently run pgbench against different servers and got some results I dont quite understand. A) EV1: Dual Xenon, 2GHz, 1GB Memory, SCSI 10Krpm, RHE3 B) Dual Pentium3 1.4ghz (Blade), SCSI Disk 10Krmp, 1GB Memory, Redhat 8 C) P4 3.2GHz, IDE 7.2Krpm, 1GBMem, Fedora Core2 All did run only postg