I am using an admittedly older MythDora (umm, 10?) system with MythWelcome set up to use the alarm to wake it up when it needs to record something, and power it off when idle.
It usually decides to act up when I am away for a week on business or something, and then everyone's mad at me when I get back!
So I finally added a "mysqlcheck --autorepair" to the bootup sequence.
As a complete aside, I just ran out of disk space while still having 100GB free... ran out of inodes. Some cron job was periodically sending emails, and I had over 500,000 unsent emails in /var/spool. Took a good while to delete all those emails.