Jean-Baptiste Jung has written a great little article for Smashing Magazine highlighting eight useful WordPress SQL Hacks. The article describes each hack, the code, and an explanation of what the code does. The most useful bit of information for me is the batch deletion of post revisions. Although post revisions are a nice thing to have, I’ve noticed I barely use them, if at all, and typically, writing a blog post in the editor can create upwards of 8 revisions. After mass deleting the revisions from my database, I noticed a sizable decrease in my overall database size.
Be wary of performing any of these hacks on a live website and please, back up all of your data before trying anything.