Re: view updates (was something else)

Aloha Kakuikanu wrote:
> So if we have views V_1, V_2, ...
> defined in terms of base relations R_1, R_2, ...
>
> V_1 = V_1(R_1, R_2, ...)
> V_2 = V_2(R_1, R_2, ...)
> ...
>
> all what we need to do is to solve the system in terms of R_1, R_2, ...
>
> R_1 = R_1(V_1, V_2, ...)
> R_2 = R_2(V_1, V_2, ...)
> ...
>
> This should be done formally, by applying laws of relational algebra.
> (Unlike classic algebra, however we face tremendous difficulties
> solving equations in RA.)

I want to add that I can't solve a system of view equations which is as simple as the union/intersection example above. And Tegiri tells me that some guys who apparently didn't even bother to study relational algebra in depth can solve this problem with some magic "category theory" technique? Received on Sat Nov 04 2006 - 02:55:58 CET