Re: Possible bridges between OO programming proponents and relational model
Date: 3 Jun 2006 06:53:59 -0700
Message-ID: <1149342839.300694.137380_at_i39g2000cwa.googlegroups.com>
Cimode wrote:
> Thank you for your feedback.
>
> << This does not make any sense, the dimension of a relvar is the
> number
> of attributes.>>Absolutely. but SQL table implementations are not
> relvar, just a possible representation of a relvar. Commonly
> implemented SQL DBMS Tables are bidimensional.
VAR CUBE RELATION { X REAL, Y REAL, Z REAL} TABLE CUBE(X REAL, Y REAL, Z REAL) What's the substantial difference with repect to 'dimensionality' ?
> <<I suppose that you know how to represent a cube with a table.>> It is
> an analogy used for communication's sake. You misread and
> misunderstood my comment. I said that a face of a cube is
> bidimensional and is a comparable to what a SQL Table is to a relvar.
> (the relvar being a 3 dimensional relvar). This analogy has been used
> by DATE and PASCAL and I find it very valid.
See above, and what analogy do you have in mind ? Received on Sat Jun 03 2006 - 15:53:59 CEST