Re: Operationalize orthogonality

From: Tony D <tonyisyourpal_at_netscape.net>
Date: 29 May 2006 08:38:39 -0700
Message-ID: <1148917119.234586.125530_at_38g2000cwa.googlegroups.com>


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.

Any real system would have to provide some basic types and operators on 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.)

However, there's a great big "!!!" sign on the road ahead; can you guess what it is yet ?

  • Tony
Received on Mon May 29 2006 - 17:38:39 CEST

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