[mythtv-users] Slow MySQL query after delete

[Michael T. Dean]

On 11/14/2008 08:29 PM, Matthew McClement wrote:
> Unless I'm missing something, it doesn't look like you re-created the
> indexes on the new table, so selects were likely resulting in a full
> table scan.
>
> Depending on how much time you have, you can usually figure out what's
> causing the performance problems by turning on slow query logging in
> MySQL and then running the queries manually, prefixed with EXPLAIN. The
> output isn't hugely complicated but the manual is your best reference to
> figuring out the
> output(http://dev.mysql.com/doc/refman/5.0/en/using-explain.html).

Though, really, a new-hardware/partial restore may actually be the best 
bet for making sure /everything/ in your database is correctly-structured.

http://www.mythtv.org/wiki/index.php/Database_Backup_and_Restore
http://www.mythtv.org/wiki/index.php/Database_Backup_and_Restore#Partial_restore_of_a_backup

Mike