From: Tom Lane <tgl@sss.pgh.pa.us>
To: Frazer McLean <frazer@frazermclean.co.uk>
cc: pgsql-general@postgresql.org
Subject: Re: Unexpected interval comparison
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Comments: In-reply-to Frazer McLean <frazer@frazermclean.co.uk>
	message dated "Tue, 21 Mar 2017 14:57:09 +0100"
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Date: Tue, 21 Mar 2017 10:42:16 -0400
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Frazer McLean <frazer@frazermclean.co.uk> writes:
> I came across an unexpected comparison (tested on PostgreSQL 9.4 and
> 9.6) for intervals with a large difference in magnitude.

>   '1 year'::interval > '32618665 years'::interval;

> Is this a bug?

It looks like the problem is overflow of the result of interval_cmp_value,
because it's trying to compute

=# select '32618665'::int8 * 30 * 86400 * 1000000;
ERROR:  bigint out of range

It's not immediately obvious how to avoid that while preserving the same
comparison semantics :-(

			regards, tom lane


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