Re: WIP: generalized index constraints
От | Jeff Davis |
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Тема | Re: WIP: generalized index constraints |
Дата | |
Msg-id | 1253119552.24770.203.camel@jdavis обсуждение исходный текст |
Ответ на | Re: WIP: generalized index constraints (tomas@tuxteam.de) |
Ответы |
Re: WIP: generalized index constraints
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Список | pgsql-hackers |
On Wed, 2009-09-16 at 15:11 +0200, tomas@tuxteam.de wrote: > One question: does the operator have to be reflexive? I.e. "A op A holds > for all A"? I don't think that reflexivity is a strict requirement. You could make this a constraint over a boolean attribute such that false conflicts with true and true conflicts with false. That would mean that your table would have to consist of either all false or all true. > I am thinking "proximity" or as you state above "similarity". May be > this is a good metaphor, leading to a good name. That's an interesting idea: "proximity constraint". I like it because (a) "proximity" might reasonably be considered a more general form of the word "unique", which might satisfy Peter's argument; (b) it conveys the use case; and (c) it sounds good. There are a couple bizarre cases where "proximity" doesn't quite fit, like my boolean example above, but I'm OK with that. Regards,Jeff Davis
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