Re: Implementation of boolean types.

>
> The expression can be collapsed. Say there are only 3 known values of
> Bonus in the Emp table (out of 10). Then
>
> totalBonus = 1000 + x1 + x2 + 2000 + x3 + 3000 + x5 + x6 + x7 =
> = 6000 + (x1 + x2 + x3 + x5 + x6 + x7) = 6000 + y
>
> An implicit rule is that expressions involving variables can be renamed
> to other variable.
>

Yes .... that's it :-) The variable names/symbol names in a relation are attribute names subscripted by primary keys. For example:

emp.bonus is {1000 EUR, bonus[petar], bonus[paul], 2000 EUR, ... }

Of course, you could change bonus[petar] to x1, bonus[paul] to x2 etc. When we augment RDBMS with this symbolic staff then we need the funcionalnity of equation solving in the engineand then things get really exicting :-)

Geetings,
Drago

P.S.: Notice the "type" of the bonus attribute. Received on Sun Jul 17 2005 - 14:06:28 CDT