Re: min() and NaN
Stephan Szabo <sszabo@megazone.bigpanda.com>
From: Stephan Szabo <sszabo@megazone.bigpanda.com>
To: Bruce Momjian <pgman@candle.pha.pa.us>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Jean-Luc Lachance <jllachan@nsd.ca>, "Michael S. Tibbetts" <mtibbetts@head-cfa.cfa.harvard.edu>, <pgsql-sql@postgresql.org>
Date: 2003-07-22T18:32:36Z
Lists: pgsql-sql
On Tue, 22 Jul 2003, Bruce Momjian wrote: > Well, my 2 cents is that though we consider NULL when ordering via ORDER > BY, we ignore it in MAX because it really isn't a value, and NaN seems > to be similar to NULL. > > When doing ORDER BY, we have to put the NULL value somewhere, so we put > it at the end, but with aggregates, we aren't required to put the NULL > somewhere, so we ignore it. Should that be the same for NaN? I just > don't see how we can arbitrarly say it is greater/less than other > values. But we already do. When doing a less than/greater than comparison, 'NaN' is considered greater than normal values which is different from NULL which returns unknown for both.