Andreas Kretschmer <akretschmer@spamfence.net> writes:
> '3 years' != '2 years 11 mons 30 days', but i got 0 rows, why?
Well, actually:
regression=# select '3 years'::interval = '2 years 11 mons 30 days'::interval;
?column?
----------
t
(1 row)
IIRC, interval comparison operators normalize the two values assuming that
1 month = 30 days. Which is kind of arbitrary, but without some such
assumption there's no way to have a scalar ordering of intervals at all.
regards, tom lane