Well, I think I've got a culprit on this one. I was seeing occasional "/tmp is out of space" messages from the server lately as well, and wondered whether these two things might be connected. It's a VPS and the /tmp partition is locked at 100MBs - can't be made larger. So I reconfigured mysql to use a separate directory for temp space, in / home. The errors stopped happening immediately (knock wood).
It begs the question as to why this fairly low-traffic Django site wanted so much /tmp space - there are dozens of WP sites on the same server with more traffic, and it's never been an issue for them. So I'm not sure about the cause, but I do seem to have found a fix. Not sure it's still relevant but here's the output of "SHOW ENGINE INNODB STATUS": http://dpaste.com/223011/ Thanks guys. ./s -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-us...@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.