Ühel kenal päeval, R, 2007-02-16 kell 17:39, kirjutas Alvaro Herrera: > Jim C. Nasby wrote: > > My suggestion would be to focus on a period data type first and > > foremost, as that's something that could be readily used by a lot of > > folks. Of particular note, it's difficult to query tables that have > > start_time and end_time fields to define a period; it's easy to screw up > > the boundary conditions, and it's also hard to make those queries > > perform well without going to extra lengths (such as defining a 'bogus' > > GiST index on something like box(point(start,start),point(end,end)). And > > it's not possible to do that in a way that avoids floating points and > > their errors. > > FWIW there's already a type called tinterval that stores (start,end). I > don't think it's very much documented; maybe it can be extended or used > as base for a new, more complete and robust type, indexable in a more > natural way, etc etc.
How easy/hard would it be to create unique indexes on tinterval (unique here meaning non-overlapping) ? Is tinterval meant to be open/closed at start and end ? -- ---------------- Hannu Krosing Database Architect Skype Technologies OÜ Akadeemia tee 21 F, Tallinn, 12618, Estonia Skype me: callto:hkrosing Get Skype for free: http://www.skype.com ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
