Be involved with MySQL Performance in some way is to ask them
what should be tuned in MySQL Server straight after installation,
assuming it was installed with default settings.
Even though you can tune quite a lot of variables in MySQL
Servers only few of them are really important for most common
workload. After you get these settings right other changes will
most commonly offer only incremental performance improvements.
key_buffer_size – Very important if you
use MyISAM tables. Set up to 30-40% of available memory if you
use MyISAM tables exclusively. Right size depends on amount of
indexes, data size and workload – remember MyISAM uses OS cache
to cache the data so you need to leave memory for it as well, and
data can be much larger than indexes in many cases. Check however
if all of key_buffer is used over time – it is not rare to see
key_buffer being set to 4G while combined size of …