Tom> It's not different from
Tom> INSERT INTO foo VALUES('1 year 1 month');
Tom> Nothing nonstandard about that that I can see.
Oh, does ISO allow a cast from a string to an interval? Yes, I think
it probably does. And with the interpretation of the string is
dependent on the ISO interval type, just like for literals? Hmm, yes,
I think it probably does...
That convinces me that you have to figure out what to do with
CAST ('1 year 1 month' AS INTERVAL MONTH)
It _still_ doesn't completely convince me that you need to (or even
want to) support hybrid interval syntax.
Though given you have to support both pg and ISO syntax in the cast, I
guess it becomes more consistent (and less implementation work) to
support both in the literal, too...
I'm concinced, I think. (For the moment :)
-roy