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From: Jasen Betts <jasen@xnet.co.nz>
Newsgroups: gmane.comp.db.postgresql.sql
Subject: Re: Round integer division
Date: 26 Jun 2010 13:09:05 GMT
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On 2010-06-25, Lee Hachadoorian <lee.hachadoorian@gmail.com> wrote:
> Is it documented anywhere that floating-point numbers round
> "scientifically", that is 0.5 rounds to the nearest even number? 

That's swiss rounding.  And no, as I understand it documented that 
most arithmetic) is platform specific.

Postgres is written in C and the relevant portions of the 
C standards douments (and discussions thereof) give a good 
picture of the functioning of postgres arithmetic.