Re: Operationalize orthogonality
Date: Sun, 04 Jun 2006 13:00:11 +0200
Message-ID: <4482bcc7$0$31648$e4fe514c_at_news.xs4all.nl>
Tony D wrote:
> The only type absolutely required is the boolean type. You could (and I
> stress, *could*) attempt to model everything from there on up in terms
> of relations and booleans, but that would require a frightening degree
> of circumlocution.
Yes. Let's not go that way.
> Any real system would have to provide some basic types and operators on
Is this rephrase ok with you?
> However, there's a great big "!!!" sign on the road ahead; can you
> those types, along with a method of generating your own types and
> associated operators. (Internally, these types and operators might be
> defined in terms of relations and booleans, but those details would be
> carefully hidden under the covers.) The only requirement on those types
> for use with relations and relational operators is that equality is
> defined. (In PostgreSQL, there is an additional requirement that
> ordering is defined if you want to use indexing on those types, so we
> might have to put that down as a requirement too.)
> guess what it is yet ?
I am looking for them. Please share the one you see. Received on Sun Jun 04 2006 - 13:00:11 CEST