Re: [PERFORM] Can the V7.3 EXPLAIN ANALYZE be trusted?

2005-02-06 Thread Leeuw van der, Tim
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Steven Rosenstein Sent: Sunday, February 06, 2005 8:51 PM To: pgsql-performance@postgresql.org Subject: [PERFORM] Can the V7.3 EXPLAIN ANALYZE be trusted? While working on a previous question I posed to t

Re: [PERFORM] [SQL] OFFSET impact on Performance???

2005-01-26 Thread Leeuw van der, Tim
Hi, What you could do is create a table containing all the fields from your SELECT, plus a per-session unique ID. Then you can store the query results in there, and use SELECT with OFFSET / LIMIT on that table. The WHERE clause for this temp-results table only needs to contain the per-session u

Re: [PERFORM] FW: Index usage

2004-11-23 Thread Leeuw van der, Tim
Well you just selected a whole lot more rows... What's the total number of rows in the table? In general, what I remember from reading on the list, is that when there's no upper bound on a query like this, the planner is more likely to choose a seq. scan than an index scan. Try to give your que

Re: [PERFORM] Tsearch2 really slower than ilike ?

2004-11-18 Thread Leeuw van der, Tim
French encodings vs. Cyrillic encodings? Characters coming thru the mail in some encoding that don't get translated properly. His name is Herve Piedvache, where the 2nd 'e' in Herve is an accented character. It must somehow do weird things to your terminal when it's trying to map that into the

Re: [PERFORM] How to speed-up inserts with jdbc

2004-11-10 Thread Leeuw van der, Tim
Hi, Try using parametrized prepared statements, does that make a difference? Or does PGSQL jdbc not support them in your version? --Tim -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Michael Kleiser Sent: Wednesday, November 10, 2004 2:52 PM To: Jeff Cc:

Re: [PERFORM] Restricting Postgres

2004-11-05 Thread Leeuw van der, Tim
To what extent would your problems be solved by having a 2nd server, a replication system (such as slony-1, but there are others), and some sort of load-balancer in front of it? The load-balancing could be as simple as round-robin DNS server, perhaps... Then when you need to do maintenance such

Re: [PERFORM] Anything to be gained from a 'Postgres Filesystem'?

2004-10-21 Thread Leeuw van der, Tim
Hi, I guess the difference is in 'severe hacking inside PG' vs. 'some unknown amount of hacking that doesn't touch PG code'. Hacking PG internally to handle raw devices will meet with strong resistance from large portions of the development team. I don't expect (m)any core devs of PG will be e

Re: [PERFORM] Anything to be gained from a 'Postgres Filesystem'?

2004-10-21 Thread Leeuw van der, Tim
Hiya, Looking at that list, I got the feeling that you'd want to push that PG-awareness down into the block-io layer as well, then, so as to be able to optimise for (perhaps) conflicting goals depending on what the app does; for the IO system to be able to read the apps mind it needs to have so

Re: [PERFORM] Select with qualified join condition / Batch inserts

2004-10-15 Thread Leeuw van der, Tim
But he's testing with v8 beta3, so you'd expect the typecast problem not to appear? Are all tables fully vacuumed? Should the statistics-target be raised for some columns, perhaps? What about the config file? --Tim -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Beh

Re: [PERFORM] Data Warehouse Reevaluation - MySQL vs Postgres --

2004-09-14 Thread Leeuw van der, Tim
Hi, -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Michael Kleiser Sent: Tuesday, September 14, 2004 4:23 PM To: Leeuw van der, Tim Cc: Steinar H. Gunderson; PostgreSQL Performance List Subject: Re: [PERFORM] Data Warehouse Reevaluation - MySQL vs Postgres

Re: [PERFORM] Data Warehouse Reevaluation - MySQL vs Postgres --

2004-09-14 Thread Leeuw van der, Tim
0PM +0200, Leeuw van der, Tim wrote: > > - PostgreSQL 7.3 running on CYGWIN with cygipc daemon > > Isn't this doomed to kill your performance anyhow? Yes and no, therefore I mentioned it explicitly as one of the caveats. When doing selects I could get performance very comparable

Re: [PERFORM] Data Warehouse Reevaluation - MySQL vs Postgres --

2004-09-14 Thread Leeuw van der, Tim
Hi, I found bulk-insert to perform very slow, when compared to MySQL / Oracle. All inserts were done in 1 transaction. However, mitigating factors here were: - Application was a .Net application using ODBC drivers - PostgreSQL 7.3 running on CYGWIN with cygipc daemon - Probably very bad tuning in

Re: [PERFORM] What is the best way to do attribute/values?

2004-08-25 Thread Leeuw van der, Tim
Hi, On Aug 25, 2004, at 4:22 AM, Mark Kirkwood wrote: > select > pav1.person_id > from > person_attributes_vertical pav1 > where > (pav1.attribute_id = 1 > and pav1.value_id in (2,3)) > or (pav1.attribute_id = 2 > and pav1.value_id in (2,3))

OT: Network config (WAS: RE: [PERFORM] postgresql performance with multimedia)

2004-08-25 Thread Leeuw van der, Tim
Hi, We're now getting very much off-topic about configuration of networking, but: - What is your OS? - What output do you get when you type 'ping localhost' in any command-prompt? -Original Message- [...] > I tried to put my_ip instead of "localhost" in > bufmng.c and it seems to work

Re: [PERFORM] I could not get postgres to utilizy indexes

2004-08-20 Thread Leeuw van der, Tim
html / rtf format? About full quoting: my apologies. -Original Message- From: Manfred Koizar [mailto:[EMAIL PROTECTED] Sent: vrijdag 20 augustus 2004 15:38 To: Leeuw van der, Tim Cc: Igor Artimenko; [EMAIL PROTECTED] Subject: Re: [PERFORM] I could not get postgres to utilizy indexes O

Re: [PERFORM] I could not get postgres to utilizy indexes

2004-08-19 Thread Leeuw van der, Tim
Hi, You asked the very same question yesterday, and I believe you got some useful answers. Why do you post the question again? You don't even mention your previous post, and you didn't continue the thread which you started yesterday. Did you try out any of the suggestions which you got yesterd

Re: [PERFORM] General performance problem!

2004-08-17 Thread Leeuw van der, Tim
Hi,   Make multi-column indexes, using the columns from your most typical queries, putting the most selective columns first (ie; you don't need to make indexes with columns in the same order as they are used in the query).   For instance, an index on cp, effectif could likely benefit both qu

Re: [PERFORM] No index usage with "left join"

2004-08-02 Thread Leeuw van der, Tim
Cannot you do a cast in your query? Does that help with using the indexes? -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: maandag 2 augustus 2004 14:09 To: [EMAIL PROTECTED] Subject: [PERFORM] No index usage with "left join" We have

Re: [PERFORM] PostgreSQL on VMWare vs Windows vs CoLinux

2004-06-02 Thread Leeuw van der, Tim
Hi All, I think it would actually be interesting to see the performance of the Cygwin version for these same benchmarks, then we've covered all ways to run PostgreSQL on Windows systems. (I expect though that performance of Cygwin-PostgreSQL will improve considerably when an updated version is

Re: [PERFORM] single index on more than two coulumns a bad thing?

2004-04-04 Thread Leeuw van der, Tim
Hi Aaron, > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of > Aaron Werman > Sent: vrijdag 2 april 2004 13:57 > > > another thing that I have all over the place is a hierarchy: > index on grandfather_table(grandfather) > index on father_table(grandfath

Re: [PERFORM] UPDATE with subquery too slow

2004-02-17 Thread Leeuw van der, Tim
Hi, This is not going to answer your question of course but did you already try to do this in 2 steps? You said that the subquery itself doesn't take very long, so perhaps you can create a temporary table based on the subquery, then in the update do a join with the temporary table? This might

Re: [PERFORM] Insert Times

2004-01-27 Thread Leeuw van der, Tim
Hi, My personal feeling on this is, that the long time taken for the first query is for loading all sorts of libraries, JVM startup overhead etc. What if you first do some SELECT (whatever), on a different table, to warm up the JVM and the database? regards, --Tim THIS COMMUNICATION MAY CONTAI