Message-ID: <19968.63.118.86.10.1176842013.squirrel@www.88thstreet.com>
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	<20070417190443.GA9094@phlogiston.dyndns.org>
Date: Tue, 17 Apr 2007 16:33:33 -0400 (EDT)
Subject: Re: Floating point type to store numbers
From: "Radhika Sambamurti" <radhika@88thstreet.com>
To: "Andrew Sullivan" <ajs@crankycanuck.ca>
Cc: pgsql-sql@postgresql.org
Reply-To: radhika@88thstreet.com
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Andrew,
This has been quite helpful. My main concern is CPU cost.  Thanks for the
input.

--Radhika

> On Tue, Apr 17, 2007 at 02:53:54PM -0400, Radhika Sambamurti wrote:
>> that hold money fields and rates from varchar to float. I do not want to
>> convert to numeric because numeric is a special string type.
>
> I think you should reconsider.  The _only_ correct storage for your
> money data (i.e. if you want to do calculations on them) is numeric.
> Float is always wrong, in every application, for this sort of work.
> Obviously, you can store the values as text, but if you want to do
> calculations, you'll need to cast (in which case you're casting to
> numeric, I hope, or you could lose precision).
>
>> The question is: how accurate is floating point numbers in Postgres. We
>
> As accurate as they are in the underlying C implementation, which is
> to say "not accurate enough for financial data".
>
> A
>
> --
> Andrew Sullivan  | ajs@crankycanuck.ca
> A certain description of men are for getting out of debt, yet are
> against all taxes for raising money to pay it off.
> 		--Alexander Hamilton
>
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> TIP 6: explain analyze is your friend
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It is all a matter of perspective. You choose your view by choosing where
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Larry Wall
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