Re: [HACKERS] Interval aggregate regression failure
Bruce Momjian <bruce@momjian.us>
From: Bruce Momjian <bruce@momjian.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@postgresql.org, Michael Glaesemann <grzm@seespotcode.net>, Michael Paesold <mpaesold@gmx.at>, PostgreSQL-patches <pgsql-patches@postgresql.org>
Date: 2006-08-31T18:57:41Z
Lists: pgsql-hackers
Tom Lane wrote: > Bruce Momjian <bruce@momjian.us> writes: > > OK, here is a much nicer patch. The fix is to do no rounding, but to > > find the number of days before applying the factor adjustment. > > You have forgotten the problem of the factor not being exactly > representable (eg, things like '10 days' * 0.1 not giving the expected > result). Also, as coded this is subject to integer-overflow risks > that weren't there before. That could be fixed, but it's still only > addressing a subset of the problems. I don't think you can fix them > all without rounding somewhere. Well, the patch only multiplies by 30, so the interval would have to span +5 million years to overflow. I don't see any reason to add rounding until we get an actual query that needs it (and because rounding is arbitrary). I think the proposed fix is the best we can do at this time. -- Bruce Momjian bruce@momjian.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +