Yeah, sorry about that :-) I really do appreciate your input -- and the previously linked page-rank example show how using manual data layout can squeeze a problem down -- but I still wonder how many of those techniques could've been made to work with SQL -- and what the resulting overhead would've been. Size on disk would probably have been a problem -- AFAIK postgres tend to compress data a bit, but probably nowhere near as much as manual rle+gzip. But I wonder how far one could've gotten with just hosting the db on a compressed filesystem...