Hi all,
Having just upgraded my MySQL server to the latest 3.23.32 version, I
thought it would be a good idea to have a review of the configuration and
try to optimise the setup further. I hope someone can help me by answering a
few queries I have.
Here's a bit of info about the spec. of the server:
* Pentium III 600 Mhz
* 512 Mb RAM
* Data directories stored on RAID 0 partition
* RedHat Linux 6.2 (with 2.2.16-22 kernel, retrofitted from RH7)
The majority of the queries to the server are from a few web servers using
PHP4, connecting using persistant connections (it normally runs with approx.
100-150 idle threads because of this).
So, I have a few questions:
1. I think I need to optimise table_cache. It's currently set to the default
of 64. There are a total of 70 tables on the system. The manual says you
should increase table_cache if the Opened_tables status variable is big. How
large is 'big'? This value is currently 274 on my system. By how much should
I increase table_cache? As a guide, the my-large.cnf sample config sets this
to 256 - would this suit my setup?
2. I currently have sort_buffer at 8 MB. The sample 'large' config suggests
1 Mb. The manual says this should be increased to improve sorts and grouping
performance - which my queries do a lot of. Performance seems fine at the
moment, but am I unnecessarily using too much memory?
3. My record_buffer is set to 16 Mb (at the suggestion of someone else). The
sample 'large' config suggests also 1 Mb. I'm not quite sure I understand
what this affects. The manual states that: "if you do many sequential scans,
you may want to increase this value" - but what kind of query would make a
sequential scan? Should I reduce this value?
Any answers gratefully accepted!
Regards,
------------------------------------------------
Basil Hussain ([EMAIL PROTECTED])
---------------------------------------------------------------------
Before posting, please check:
http://www.mysql.com/manual.php (the manual)
http://lists.mysql.com/ (the list archive)
To request this thread, e-mail <[EMAIL PROTECTED]>
To unsubscribe, e-mail <[EMAIL PROTECTED]>
Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
