From: | tomas(at)tuxteam(dot)de |
---|---|
To: | Jeff Davis <pgsql(at)j-davis(dot)com> |
Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Brendan Jurd <direvus(at)gmail(dot)com>, Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: WIP: generalized index constraints |
Date: | 2009-09-16 13:11:14 |
Message-ID: | 20090916131114.GA19820@tomas |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On Tue, Sep 15, 2009 at 10:28:28AM -0700, Jeff Davis wrote:
> On Tue, 2009-09-15 at 13:16 -0400, Robert Haas wrote:
> > Uhh.... so what happens if I create an index constraint using the
> > +(integer, integer) operator?
>
> You can use any operator that has an index search strategy. Overlaps is
> probably the most useful, but you could imagine other operators, like a
> bi-directional containment operator (either LHS is contained in RHS, or
> vice-versa).
>
> You can also get creative and have a "similarity" operator that
> determines whether two tuples are "too similar". As long as it is
> symmetric, the feature will work.
One question: does the operator have to be reflexive? I.e. "A op A holds
for all A"?
I am thinking "proximity" or as you state above "similarity". May be
this is a good metaphor, leading to a good name.
Regards
- -- tomás
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (GNU/Linux)
iD8DBQFKsOPyBcgs9XrR2kYRAhsUAJkBICYUMK0tDrycPbctiGF7YKI/9gCeLQzq
DPyAAkMgZJFn8BZ7P8119/g=
=lVz1
-----END PGP SIGNATURE-----
From | Date | Subject | |
---|---|---|---|
Next Message | Alvaro Herrera | 2009-09-16 13:57:50 | Re: errcontext support in PL/Perl |
Previous Message | C Wise | 2009-09-16 13:06:18 | PGCon/West in Seattle |