Re: [PERFORM] Postgres server getting slow!!

2005-01-29 Thread N S
  Thanks tom. I checked the client side software. The software closes connection when connected locally. But when connected through dialup, this problem comes. I will check the ppp connection also. Is there any method of killing old pids. And also any performance tuning to be done on postgresql.

Re: [PERFORM] Performance problem with semi-large tables

2005-01-29 Thread Ken Egervari
Thanks again for your response. I'll try and clarify some metrics that I took a few days to figure out what would be the best join order. By running some count queries on the production database, I noticed there were only 8 rows in release_code. The filtered column is unique, so that means th

Re: [PERFORM] Performance problem with semi-large tables

2005-01-29 Thread PFC
So are you suggesting as a general rule then that sub-queries are the way to force a specific join order in postgres? If that is the case, I will do this from now on. I'll try to explain a bit better... Here's your original query : select s.*, ss.* from shipment s, shipment_status

Re: [PERFORM] Performance problem with semi-large tables

2005-01-29 Thread Ken Egervari
Well, postgres does what you asked. It will be slow, because you have a full table join. LIMIT does not change this because the rows have to be sorted first. I am aware that limit doesn't really affect the execution time all that much. It does speed up ORM though and keeps the rows to a managea

Re: [PERFORM] Performance problem with semi-large tables

2005-01-29 Thread Ken Egervari
Yes, I'm very well aware of VACUUM and VACUUM ANALYZE.  I've even clusted the date index and so on to ensure faster performance. - Original Message - From: David Parker To: Ken Egervari ; pgsql-performance@postgresql.org Sent: Saturday, January 29, 2005 5:04 PM

Re: [PERFORM] Performance problem with semi-large tables

2005-01-29 Thread PFC
select s.*, ss.* from shipment s, shipment_status ss, release_code r where s.current_status_id = ss.id and ss.release_code_id = r.id and r.filtered_column = '5' order by ss.date desc limit 100; Release code is just a very small table of 8 rows by looking at the production data, hence the

Re: [PERFORM] Performance problem with semi-large tables

2005-01-29 Thread David Parker
You don't mention if you have run VACUUM or VACUUM ANALYZE lately. That's generally one of the first things that folks will suggest. If you have a lot of updates then VACUUM will clean up dead tuples; if you have a lot of inserts then VACUUM ANALYZE will update statistics so that the planner

Re: [PERFORM] Performance problem with semi-large tables

2005-01-29 Thread Josh Berkus
Ken, Actually, your problem isn't that generic, and might be better solved by dissecting an EXPLAIN ANALYZE. > 1. Should I just change beg to change the requirements so that I can make > more specific queries and more screens to access those? This is always good. > 2. Can you > recommend way

Re: [PERFORM] PostgreSQL clustering VS MySQL clustering

2005-01-29 Thread Christopher Weimann
On 01/28/2005-05:57PM, Alex Turner wrote: > > > > Your system A has the absolute worst case Raid 5, 3 drives. The more > > drives you add to Raid 5 the better it gets but it will never beat Raid > > 10. On top of it being the worst case, pg_xlog is not on a separate > > spindle. > > > > True for

Re: [PERFORM] PostgreSQL clustering VS MySQL clustering

2005-01-29 Thread Christopher Weimann
On 01/28/2005-10:59AM, Alex Turner wrote: > At this point I will interject a couple of benchmark numbers based on > a new system we just configured as food for thought. > > System A (old system): > Compaq Proliant Dual Pentium III 933 with Smart Array 5300, one RAID > 1, one 3 Disk RAID 5 on 10k R

[PERFORM] Performance problem with semi-large tables

2005-01-29 Thread Ken Egervari
Hi everyone.   I'm new to this forum and was wondering if anyone would be kind enough to help me out with a pretty severe performance issue.  I believe the problem to be rather generic, so I'll put it in generic terms.  Since I'm at home and not a work (but this is really bugging me), I can'

Re: [PERFORM] Postgres server getting slow!!

2005-01-29 Thread Tom Lane
"Narayanan Subramaniam Iyer" <[EMAIL PROTECTED]> writes: > 1) When 3 or 4 clients connect to this server, the pids are created and > those pids are not killed even after the client disconnects. In that case your clients are not really disconnecting. Take a closer look at your client-side software

[PERFORM] Postgres server getting slow!!

2005-01-29 Thread Narayanan Subramaniam Iyer
  Hi   i am running a High availability Postgresql server on redhat linux 9. I am using NFS mount of data directory from a shared storage. The server was running without problems for last two months. The server is connected to a dialin router where all my company units dialin and update the dat

Re: [PERFORM] Optimizing Outer Joins

2005-01-29 Thread Sebastian Böck
Richard Huxton wrote: Sebastian Böck wrote: But why is the scan on table b performed? If i understand it correctly this is unnecessary because the result contains only rows from table a. It's only unnecessary in the case where there is a 1:1 correspondence between a.id and b.id - if you had more

Re: [PERFORM] PostgreSQL clustering VS MySQL clustering

2005-01-29 Thread William Yu
I know what I would choose. I'd get the mega server w/ a ton of RAM and skip all the trickyness of partitioning a DB over multiple servers. Yes your data will grow to a point where even the XXGB can't cache everything. On the otherhand, memory prices drop just as fast. By that time, you can ebay yo