On Jun20, 2011, at 19:16 , Merlin Moncure wrote: > On Mon, Jun 20, 2011 at 11:21 AM, Jeff Davis <pg...@j-davis.com> wrote: > hm, what if there *was( only one range type per base type, but in the > various contexts where specific ordering and collation was important > you could optionally pass them in? Meaning, the specific ordering was > not bound rigidly to the type, but to the operation?
I suggested that previously here http://archives.postgresql.org/pgsql-hackers/2011-06/msg00846.php In the ensuing discussion, however, it became clear that by doing so range types become little more than a pair of values. More specifically, a range then *doesn't* represent a set of values, because whether or not a value is "in" the range depends on a specific sort order. Actually, you'd probably even loose the possibility of having a normalization function for discrete base types (which makes sure that we know that "[1,2]" is the same as "[1,3)"), because it's hard to image one normalization function that works sensibly for two different orderings. So by doing that, you effectively turn a RANGE into a quadruple (lower type, lower_included bool, upper type, upper_included bool). best regards, Florian Pflug -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
