Re: Floating point problem? - Mailing list pgsql-bugs

From Tom Lane
Subject Re: Floating point problem?
Date
Msg-id 22366.1151352672@sss.pgh.pa.us
Whole thread Raw
In response to Floating point problem?  (Chito Lapena <chito@webims.com>)
List pgsql-bugs
Chito Lapena <chito@webims.com> writes:
> This has become more of a prominent problem as we've added more data
> integrity checks in our code... We are getting errors like the following
> from our debug output:

> EMP ID: 3 Ledger balance mismatch - record: 116.1 Ledger: 116.1 diff:
> 1.52588e-05

> record: float4
> ledger: float4

If you are expecting exact results, you should be using an exact
datatype, ie numeric.  Floating-point calculations are inherently
inexact ... *especially* with float4, which only has about six
significant digits at best.

            regards, tom lane

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