Fedora Linux Support Community & Resources Center
  #1  
Old 20th January 2005, 07:16 AM
mufeed_usman Offline
Registered User
 
Join Date: Jan 2005
Location: India
Posts: 6
postgres application running slow

Greetings folks,

A client of the firm where I work sent a complaint stating that their application (banking software) developed in VB has begun to slow down when they excute certain queries. The DB is maintained using postgreSQL and the server is running on fedora. Nodes are all windows machines.

This is what I'd like to know - Is there anything that could be done on the server to overcome their stated problem?

Under normal circumstances what are all the things I need to do to tune a system running on fedora, like defrag in windows?

Regards,
Mufy

Last edited by mufeed_usman; 20th January 2005 at 07:18 AM.
Reply With Quote
  #2  
Old 20th January 2005, 08:53 PM
james_in_denver Offline
Registered User
 
Join Date: Oct 2004
Posts: 1,227
Well, it most likely is not a Linux issue as much as it is a database issue.

I would recommend starting with the SQL code that is being executed on the front end. Make sure that as many queries as possible use indexes,

Also, it sounds as if performance for the database was acceptable at the begining of the project, and has slowed down? this is most likely due to increased volumes of data. One thing you can do to optimize Postgres is to place/move some of the indexes and/or tables on seperate disks. This can dramatically improve I/O performance.

If this database is used with a lot of records being inserted and deleted, you may need to run the "vacuumdb" command to "coalesce" free space in your tables.

The one place I would recommend starting with though is query tuning, make sure that you have the right indexes in place for the queries being executed.
__________________
Only dead fish go with the flow....

Hmmm, what did I miss?
Reply With Quote
  #3  
Old 20th January 2005, 08:55 PM
ewdi Offline
Retired Admin
 
Join Date: Jan 2004
Location: Penguin Land
Age: 64
Posts: 1,939
what version of postgree?if it's the latest do you guys enable UTF?
__________________
+ Visit My new blog
- [B]SlashGear US, SlashGear Japan, and
+Founder & Admin of www.fedoraforum.org

Follow me at http://twitter.com/ewdi

Laptop : MacBook Pro 2.4Ghz 4GB DDR, 20-inch iMac Aluminium/4GB RAM
Reply With Quote
  #4  
Old 21st January 2005, 09:55 PM
Mossy Offline
Registered User
 
Join Date: Jan 2005
Posts: 12
1) Make sure you have vacuumed & analyzed your DB on a regular basis. Note that you can actually lose your entire DB due to the XID wraparound issue if you don't vacuum. (Maximum of 4 billion transactions before the IDs wrap around and your data is dead -- vacuum resets the counter each time.) This is roughly the schedule I use -- hourly analyze, nightly vacuum, weekly vacuum full. There's also an autovacuum daemon that detects when your tables have been updated enough to require analyze or vacuum.

2) Check your postgres configuration. The default config is designed to run under extremely old machines and runs very poorly in any sensible server environment. If nobody has ever touched the config, postgres is probably running in crippled mode. The following is a pretty good link to read up.

http://www.varlena.com/varlena/Gener...bits/perf.html

3) Check your hardware config. RAID-1 for OS + WAL, RAID-10 for Postgres database is the optimal solution. Some people say RAID-5 reaches parity with RAID-10 when you hit 8+ hard drives.

4) Examine the queries using the EXPLAIN ANALYZE command. Even if you have indexes on elements, it's possible they aren't being used due to data type mismatches or the statistics tell the query planner a seqscan would be faster. (Whether it actually is or not requires further analysis.)


Quote:
Originally Posted by mufeed_usman
Greetings folks,
A client of the firm where I work sent a complaint stating that their application (banking software) developed in VB has begun to slow down when they excute certain queries. The DB is maintained using postgreSQL and the server is running on fedora. Nodes are all windows machines.
Reply With Quote
Reply

Tags
application, postgres, running, slow

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Gnome, FC9: crash when running gpk-application sionut Using Fedora 1 22nd May 2008 09:14 AM
Running Application on startup Old_Midhurstian Using Fedora 5 21st June 2007 01:46 PM
Running application from ISO9660 CD fitzbewlnx Using Fedora 5 18th May 2007 09:46 PM
Slow Application Launch Sammy Using Fedora 4 29th March 2005 01:04 AM


Current GMT-time: 12:15 (Wednesday, 22-10-2014)

TopSubscribe to XML RSS for all Threads in all ForumsFedoraForumDotOrg Archive
logo

All trademarks, and forum posts in this site are property of their respective owner(s).
FedoraForum.org is privately owned and is not directly sponsored by the Fedora Project or Red Hat, Inc.

Privacy Policy | Term of Use | Posting Guidelines | Archive | Contact Us | Founding Members

Powered by vBulletin® Copyright ©2000 - 2012, vBulletin Solutions, Inc.

FedoraForum is Powered by RedHat
Deblin - Huelva - Plock Instagram Photos