Message-ID: <bc1b85d65c284e3aaa718eba5f43dd4b970ccf33.camel@cybertec.at>
Subject: Re: Rounding strategy
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: rudolphfroger@dreamsolution.nl, pgsql-docs@lists.postgresql.org
Date: Thu, 22 Apr 2021 18:54:54 +0200
In-Reply-To: <40dea1e0254dc00213f0dd10afa5e668abf0d020.camel@cybertec.at>
References: <161881920775.685.12293798764864559341@wrigleys.postgresql.org>
	 <40dea1e0254dc00213f0dd10afa5e668abf0d020.camel@cybertec.at>
Content-Type: multipart/mixed; boundary="=-XnRDfRTR5K86J6wSbh5L"
User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) 
MIME-Version: 1.0
Archived-At: 
 <https://www.postgresql.org/message-id/bc1b85d65c284e3aaa718eba5f43dd4b970ccf33.camel%40cybertec.at>
Precedence: bulk


--=-XnRDfRTR5K86J6wSbh5L
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit

On Mon, 2021-04-19 at 08:00 +0000, PG Doc comments form wrote:
> The 'round' mathematical function documentation doesn't specify its rounding
> strategy. If this would be documented then users can rely on its rounding
> behavior. For double precision the rounding probably depends on your
> platform. For numeric the function seems to round to nearest with ties going
> away from zero (sometimes referred to as "round half up). 6.5 -> 7.0 and
> -6.5 -> -7.0.

Here is a proposed patch.

Yours,
Laurenz Albe

--=-XnRDfRTR5K86J6wSbh5L
Content-Disposition: attachment;
 filename="0001-Document-tie-breaking-behavior-of-round.patch"
Content-Transfer-Encoding: base64
Content-Type: text/x-patch;
 name="0001-Document-tie-breaking-behavior-of-round.patch";
	charset="UTF-8"
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--=-XnRDfRTR5K86J6wSbh5L--