The aliases were quoted, so I don't think they are a problem.
Check the spelling of "pop_stdev". In your query you only had one "d" but you talk about "pop_stddev" and Amul said it is actually called "stddev_pop".
I am told pop_stddev(integer) does not exist and explicit type casting may help. I'll be reading up on that in the next few minutes and see if I can get this working. I know why the aliases were a problem or would have been a problem too, the first word in every one of them that don't work now was population with a blank space following it so psql probably thought this idiot is trying to hang four aliases on a single string so I got a yellow card for my efforts. The pop_stddev() is an aggregate but one I've never used before inside psql or sql.
