Check in on your status variables in MySQL.

So you have your database running as well as expected.
But is it ? Could it be operating better?

When is the last time you checked on some of your status variables ?

Some key status variables to monitor are:

• Sort_merge_passes
• I monitor clients systems. This is one variable that I see a vast range of values for. 
• If you see a high value for this status you should seriously consider looking into adjusting the sort_buffer_size. Peter's blog post can be a helpful start in evaluating your options. 
• http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html#sysvar_sort_buffer_size
• sort_buffer_size
• A valid value takes some review and testing. Adjustments can help your performance with order by and group by result sets. 
• Again review Peter's post to help you evaluate. 
• http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html#sysvar_sort_buffer_size
• Select_scan
• "The number of joins that did a full scan of the first table" 
• Do you really want full scans?
• Handler_read_first
• "If this value is high, it suggests that the server is doing a lot of full index scans;"
• again do you want full scans? 
• Key_reads
• "If Key_reads is large, then your key_buffer_size value is probably too small.
• Select_full_join
• "If this value is not 0, you should carefully check the indexes of your tables."

So to put it simply.... check your status !