Re: Range types

Jeff Davis <pgsql@j-davis.com> writes:
> [ hacky special-case representation for discrete timestamp ranges ]

I'm still not exactly clear on what the use-case is for discrete
timestamp ranges, and I wonder how many people are going to be happy
with a representation that can't handle a range that's open-ended
on the left.

> So, the idea is to default to a continuous range type, but if the user
> supplies a granule, prior and next functions, and other necessary
> details, then it becomes a discrete range type.

Huh?  You're not going to be able to have a special case data
representation for one or two data types at the same time as you have a
function-based datatype-independent concept of a parameterized range
type.  Well, maybe you could have special code paths for just date and
timestamp but it'd be horrid.

More importantly, the notion of a representation granule is still 100%
wishful thinking for any inexact-representation datatype, which is going
to be a severe crimp in getting this accepted for timestamp, let alone
defining it in a way that would allow users to try to apply it to
floats.  Float timestamps might not be the default case anymore but they
are still supported.

I think you should let go of the feeling that you have to shave bytes
off the storage format.  You're creating a whole lot of work for
yourself and a whole lot of user-visible corner cases in return for
what ultimately isn't much.
        regards, tom lane