Re: Jan's well-defined view updates definition

From: Mikito Harakiri <mikharakiri_at_ywho.com>
Date: Tue, 16 Sep 2003 19:07:49 -0700
Message-ID: <quP9b.30$cW6.173@news.oracle.com>

We can't continue going round and round, so let's move on to the second paragraph of your definition.

"Jan Hidders" <jan.hidders_at_pandora.be> wrote:
> Finally, we define a view V as *updatable* by a certain set of updates U
if
> for all databases D that satisfy the schema all updates in U are
> well-defined. Additionally we say that V is *commutatively updatable* by U
> if for all databases D that satisfy the schema it holds that if two series
> of updates from U have the same result when applied to Q(V) and perform
> only well-defined updates then they result in the same database when
> applied to D.

Could you please provide a non-commutatively updatable example that we can discuss? Received on Tue Sep 16 2003 - 21:07:49 CDT