On Sun, Oct 24, 2010 at 6:59 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Jeff Davis <pg...@j-davis.com> writes: >> Last development cycle, one of the questions that was unresolved was >> whether to handle ranges like a discrete set (that is, [1,5) = [1,4] ) >> or continuous or both. > > Put me in the camp that says you need both. I really seriously dislike > the idea of representing [1, 2) as [1, 2-epsilon], mainly because there > is often no portable value for epsilon. Dump-and-restore would be quite > hazardous.
+1. I think the right way to do this is - in general, a range should be stored as a start value, a stop value, and 2 extra bits indicating whether each end is open or closed. (And perhaps a few bits beyond that if you want to support things like (4, inf) over a base type that has no infinite value, which I'm not sure about.) Then you can optionally allow a "convert-to-closed" operation, which will convert a [3, 5) over int to [3, 4], but be undefined for float/timestamp ranges. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
