From: Lew <lew@nospam.lewscanon.com>
To: pgsql-sql@postgresql.org
Subject: Re: Floating point type to store numbers
Date: Sat, 21 Apr 2007 01:20:46 -0400
Message-ID: <BN-dnWNvp_KzArTbnZ2dnUVZ_uninZ2d@comcast.com> (raw)
In-Reply-To: <20070417205318.GC9094@phlogiston.dyndns.org>
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<20070417190443.GA9094@phlogiston.dyndns.org>
<19968.63.118.86.10.1176842013.squirrel@www.88thstreet.com>
<20070417205318.GC9094@phlogiston.dyndns.org>
Andrew Sullivan wrote:
> On Tue, Apr 17, 2007 at 04:33:33PM -0400, Radhika Sambamurti wrote:
>> Andrew,
>> This has been quite helpful. My main concern is CPU cost. Thanks for the
>> input.
>
> You're welcome. Are you sure your main concern should be CPU cost?
> It's true that numeric is more costly that float in a lot of cases,
> but I know at least one auditor who will refuse to certify results
> from programs that anywhere use floating-point storage or calculation
> on accounting data. The problem is really that you can get compound
> errors -- very small rounding errors several times can turn out to be
> a big problem. (One quick primer that can help you understand this
> is at <http://www2.hursley.ibm.com/decimal/decifaq1.html;.)
Would you rather have wrong answers really, really fast, or right answers fast
enough?
--
Lew
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To: pgsql-sql@postgresql.org
Cc: lew@nospam.lewscanon.com
Subject: Re: Floating point type to store numbers
In-Reply-To: <BN-dnWNvp_KzArTbnZ2dnUVZ_uninZ2d@comcast.com>
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