Take the 2-minute tour ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

i have a query which execution takes 15s on the server. the server is bi-xeon 5130 (2GHz) with 2GB of RAM and 160GB of scsi hardrive in RAID. Database is PostgreSQL 8.1 on Debian 4 etch.

This query is executed by an ERP (openerp), so i can't change or modify it. i can test it as i want,i can reproduce the long time as i want, i got it in the log file and reproduce the case into pgadmin.

Copy/pasted into a txt file, the simple query need 170Kb to be stored (just the text query).

During the execution, linux (by 'top' commandline) tell me that postgres use 99-100% of the CPU but only 6% of RAM.

So, how can i increase the performance of postgres to gain time in this query execution. a parameter somewhere ? in Postgres ? in linux ?

The query is like this:

SELECT
    id
FROM
    sale_order_line
WHERE
    (state IN ('confirmed', 'confirmed_wait', 'manquant'))
    AND
    (id IN (27405, 27399, 16583, 27395, XXX))
ORDER BY 
    id DESC LIMIT 50;

[replace the XXX by a list of 20000 id ! ]

yes this is a monster query but not a complicated one , very simple in fact.

thanks for help. i search for a long time (2 weeks already...)

share|improve this question

1 Answer 1

There are a number of steps to take here:

  • Optimise the PostgreSQL config so it uses the correct amount of your system resources (see this article I wrote for a previous employer for my full set of tips on this front);
  • You need to optimize the database schema -- specifically, the indexes therein -- to make the database run as efficiently as possible. For that, see this article on query tuning written by a colleague of mine at said former job. It covers both MySQL and PostgreSQL, but just the relevant bits should get you along the way to the ultimate solution.
share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.