Re: On view updating

"Tony Andrews" <andrewst_at_onetel.com> wrote in message news:1095695006.709332.227670_at_h37g2000oda.googlegroups.com...

> Both views return those employees who belong to a department based in
> London. But the first is a join view, and so a DELETE from this
> corresponds to a DELETE from emp AND dept; the second corresponds only
> to a DELETE from emp. Yet the optimiser might well transform one form
> into the other (unless it takes account of this - in which case
> optimisation options have been reduced).
>

You've lost me. Why would the first view have to delete any departments?

While we're at it, column wildcarding and logical data independence interact with each other.

If, after you define one of these views that retireves "emp.*", I come along and "ALTER TABLE emp ADD COLUMN
fubar TEXT NOT NULL" should your view now return the new column or not? Should your view suddenly become "non insertable?" Received on Mon Sep 20 2004 - 21:17:56 CEST