I am looking at ways to slim some of my wordpress blogs, to reduce CPU load and improve MySQL access times etc.

One thing I am looking at is removing old posts that haven't been read for a while. But I can't figure out an effective way of doing this. I started with a LIKE comparison between the posts and the statpress tables, but unsurprisingly it near enough killed mysql. I'm not really that surprised.

SELECT * FROM wp_posts,wp_statpress WHERE wp_posts.guid LIKE CONCAT("%",wp_statpress.urlrequested,"%")

I was going to look for NULL records and hence pick out the posts that aren't in the statpress table.

Anybody any ideas how I could do a query something similar without killing the server.