How to gain performance through MySQL

[Rich]

Andreas Baier wrote:
> Hello,
> 
> First excuse my bad english, I'll try to give my best.
> 
> A few weeks ago, I changed amarok from svn-version to the current stable 
> release (1.4.5 r1). I use gentoo-linux and amarok with mysql backend.

even though i don't remember db changes after 1.4.5, downgrading is not 
supported....

> Now, when I change ratings, skip songs, amarok AND mysql are using 90-100% of 
> cpu-time for more than 3 seconds and surface of amarok is freezing for this 
> time (the music is played normally, no stuttering of sound or so).

...but we can still try to resolve the problem :)
do you want to keep your statistics, ratings, playcounts etc ?
if so, create a backup of the db and try with a fresh database.
if you don't want to keep them and this helps, well, good :)

what is the exact mysql version ? have you changed that lately ?
can you upgrade to the latest mysql ?

if nothing helps, you can try logging mysql queries to see whether it is 
amarok overwhelming mysql, or is it mysql being weird.
...
-- 
  Rich