Not yet. I wasn't sure how to go about the __PACKAGE__->set_sql part as a mixin. I knew how to get count_where mixed in, but not the set_sql call. I guess I could use caller (?) to determine who was 'use'ing my module, and run the set_sql in that namespace... I think. Or am I missing something more basic?

Well, I got it all working as a mixin. Now I'm working on adding the other aggregate functions (min/max/etc). Then I'll see if I can get that working, and submit to cdbi list for comment.