Further to Sean's excellent presentation this evening; I had a look at the default config for mysql.

mysql source code comes with a directory called "support-files" that (among other things) contains a set of recommended default config files.

my-huge.cnf my-innodb-heavy-4G.cnf my-large.cnf my-medium.cnf my-small.cnf

grepping for query_cache_size reveals that my-huge.cnf, my-innodb-heavy-4G.cnf, and my-large.cnf have the query_cache activated by default.

Keep in mind these configs were originally created back in the day when 1G of memory was considered huge, I think most typical web servers can run with my-huge.cnf and a single user system (like a laptop) can use my-medium.cnf.

The settings in my-huge.cnf look pretty reasonable and agree with the settings Sean was recommending.

I mentioned that mysql creates .bin files when doing replication which is turned ON by default so the setting you should comment out is "log-bin" unless you are doing replication. This is especially true if you are doing lots of updates to your data.

For example, I have a client that replicates a large access to database to mysql several times per day. The entire database is dropped and reloaded each time and this ended up exhausting many gigs of disk space just in mysql .bin files (and imagine how inefficient creating them was!).

Just for interest sake, I checked some SUSE installs and the my-medium.cnf was the default so on a production web server this should be changed. The my-huge.cnf is included in the install but is not the default.

Regards,

John