Re: WIP: generalized index constraints
Robert Haas <robertmhaas@gmail.com>
From: Robert Haas <robertmhaas@gmail.com>
To: Peter Eisentraut <peter_e@gmx.net>
Cc: Jeff Davis <pgsql@j-davis.com>, Brendan Jurd <direvus@gmail.com>, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, pgsql-hackers@postgresql.org
Date: 2009-09-16T17:54:33Z
Lists: pgsql-hackers
On Wed, Sep 16, 2009 at 3:14 AM, Peter Eisentraut <peter_e@gmx.net> wrote: > On Tue, 2009-09-15 at 12:37 -0400, Robert Haas wrote: >> Instead of calling these generalized index constraints, I wonder if we >> oughtn't to be calling them something like "don't-overlap constraints" >> (that's a bad name, but something along those lines). They're not >> really general at all, except compared to uniqueness constraints (and >> they aren't called generalized unique-index constraints, just >> generalized index constraints). > > What they should be called is generalized unique constraints, without > reference to "index". Because what they generalize is the operator by > which uniqueness is determined. Well, it should eventually be possible to use this feature to create an index which excludes overlapping ranges in fact, unless I misunderstand, that's the principle likely use case. Which is not unique-ness at all. ...Robert