On Fri, Apr 9, 2010 at 7:18 PM, Nathan Boley <npbo...@gmail.com> wrote: >> The advantage of specifying a + and a - in the type interface is that >> the unit definition can then be specified as part of the type >> declaration itself. So you can do: >> >> CREATE TYPE ts_sec AS RANGE OVER timestamp (UNIT = '1s'); >> CREATE TYPE ts_min AS RANGE OVER timestamp (UNIT = '1m'); >> >> All of the stuff about defining + and - is hidden from the user - it's >> part of the type interface, which is pre-created. > > The disadvantage is that it does not permit irregularly spaced units.
True. The only types I can think of that have irregularly spaced units would be things based on floating points, and I was assuming that people would only want continuous intervals on those. If someone really wants to be able to deduce that [1.0,3.0) = [1.0,3.0-epsilon), then we need a different design. But I find it hard to believe that's very useful. Maybe you feel otherwise? ...Robert -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers