Is there a way to extract the total amount of time in a given unit from an interval? For example, I would like to know the total number of milliseconds in an interval.
The expression
select extract('seconds' from '5 minutes'::interval)
returns the value of the seconds field (0) in the interval; not the total number of seconds in the interval. Is there a function like extract, but which extracts the value not *from* the given field, but *in* the given units (the opposite of the justify* functions)?
I started using the interval type because it a) looks nice in result sets (e.g., 01:02:00); and b) can do arithmetic with timestamps. However, since I'm going to need to be able to convert to and from milliseconds for my application, I'm wondering if I wouldn't be better off just using a numeric type for storing the intervals in seconds (the intervals would be no more than a day total). Thoughts?
Thanks
Andrew