I tend to optimize all of our tables around once per week. However the last
4 or 5 times I have optimized a particular table it takes take a really
long time (about 25 minutes compared with 50 seconds 5 weeks ago).

SHOW FULL PROCESSLIST shows 'Repair with keycache'.

This means a repair is in progress, so an error must have been found. Can
anyone shed any light on why this might happen EVERY time I optimize this
table, and not any of the other tables?

A few facts about the table:

MyISAM
4,219,000 rows
574MB data
406MB index
Each time it is optimized there is around 120,000 new rows.

Mysql 4.0**

** For performance reasons we use an old version as 4.1 was 15-20% slower
for us when we looked into upgrading and did some real-world benchmarks.
We will be testing 5.0 in a few weeks.



--
Brian Wakem
Email: http://homepage.ntlworld.com/b.wakem/myemail.png