How much table overhead is too much?

Question

I just saw in phpMyAdmin that one of our MySQL tables is 14MB in size, but has 10MB overhead. I'm guessing this is a lot!

How much is too much? Should I run OPTIMIZE TABLE regularly?

Answer 1

"Overhead" is not yet reclaimed space formerly occupied by now deleted records. If you're doing a lot of inserts / deletes, it's pretty much always going to be there. You can run OPTIMIZE TABLE, but I wouldn't bother - especially on large tables (14M is not large, though) where it can take a lot of time.