PostgreSQL v Informix

In article <01bc6cbf$995c07f0$7e14a5ce@blackie>, "T. Nimmo" <nimmo@primenet.com> wrote: >... I couldn't trust my "PERSONAL ENTERPRISE" data with something like >this. > >Examples: >Dropping a table twice causes corruption, We've had versions of Informix that (quietly) refuse to drop temporary tables, only to explode later when you attempt to recreate them. > drop/create not rollback-able Informix doesn't cope with this either. >-SUM aggregate on no rows or null value should return NULL, not >zero(Thomas) While Informix does return a NULL on a SUM of no rows, and I assume that's in the SQL standard somewhere, can anybody explain to me *why*? If my question is: SELECT SUM(quantity_sold) FROM orders WHERE city = "Tokoroa" and I've not sold anything in Tokoroa, shouldn't the answer be zero? The answer isn't "undefined" or "unknown", is it? Hmmm, maybe it *is* undefined, but it still doesn't really make sense to me. My point in this posting? Buggered if I know really, I guess I was just amused at the list of terrible short-comings in this freeware database vs the All-Mighty Informix. (Yes, I know there were more serious issues raised in the original posting) Kerry S ------------------------------------,------------------------------------------ Kerry Sainsbury, kerry@kcbbs.gen.nz | THE INFORMIX FAQ v2.10 May 1997 Quanta Systems, Auckland | http://www.iiug.org/techinfo/faq/ New Zealand. Work: +64 9 377-4473 | ftp://ftp.iiug.org/pub/informix/faq Home: +64 9 279-3571 | ftp://kcbbs.gen.nz:/pub/informix/