Unexpected interval comparison

Originally asked on pgsql-general[1]/messages/by-id/1490104629.422698.918452336.26FA96B7@webmail.messagingengine.com.

[1]: /messages/by-id/1490104629.422698.918452336.26FA96B7@webmail.messagingengine.com

I came across an unexpected comparison (tested on PostgreSQL 9.4 and

9.6) for intervals with a large difference in magnitude.

I narrowed it down to this example, where comparisons within this range
give the wrong value:

postgres=# SELECT

'1 year'::interval > '3854933 years'::interval,

'1 year'::interval > '3854934 years'::interval,

'1 year'::interval > '32618664 years'::interval,

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

?column? | ?column? | ?column? | ?column?

----------+----------+----------+----------

f | t | t | f

(1 row)

Kind regards,

Frazer McLean