PostgreSQL: format interval as minutes

Question

When I subtract timestamps, the interval is in form DD:HH:MM:SS. How can I convert it all to minutes without extracting days and hours and multiplication/addition

Answer 1

I don't actually think you can without doing a bunch of weirdness (like to_char) because minutes roll over at 59. Which is why you get:

postgres=# select date_part('minutes', '65 minutes'::interval);
 date_part 
-----------
         5
(1 row)

postgres=# select '65 minutes'::interval
postgres-# ;
 interval 
----------
 01:05:00
(1 row)