From: Tom Lane <tgl@sss.pgh.pa.us>
To: Chapman Flack <chap@anastigmatix.net>
cc: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>,
        Joe Nelson <joe@begriffs.com>, pgsql-hackers@postgresql.org
Subject: Re: POC: rational number type (fractions)
In-reply-to: <5EC3031C.6020105@anastigmatix.net>
References: <20200208042554.GE42864@begriffs.com>
 <0e2422da-953b-6b96-1900-f67c7e5e3307@2ndquadrant.com>
 <5EC3031C.6020105@anastigmatix.net>
Comments: In-reply-to Chapman Flack <chap@anastigmatix.net>
	message dated "Mon, 18 May 2020 17:50:20 -0400"
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Date: Mon, 18 May 2020 18:14:36 -0400
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Chapman Flack <chap@anastigmatix.net> writes:
> On 05/18/20 17:33, Peter Eisentraut wrote:
>> The numeric type already stores rational numbers.  How is this different? 
>> What's the use?

> Won't ever quite represent, say, 1/3, no matter how big you let it get.

There surely are use-cases for true rational arithmetic, but I'm
dubious that it belongs in core Postgres.  I don't think that enough
of our users would want it to justify expending core-project maintenance
effort on it.  So I'd be happier to see this as an out-of-core extension.

(That'd also ease dealing with the prospect of having more than one
variant, as was mentioned upthread.)

			regards, tom lane