is pivoted phones view updateable?
From: Aloha Kakuikanu <aloha.kakuikanu_at_yahoo.com>
Date: 9 Nov 2006 11:30:34 -0800
Message-ID: <1163100632.278935.65480_at_b28g2000cwb.googlegroups.com>
Tchuzhie Giri wrote:
> It is not "OK" so long as one does not have your rules of updatability.
> You put a pile of symbols on the pile of symbols: it does not have
> sense without the rules. Please provide the rules, simple examples
> and then one can go to more complex examples.
Date: 9 Nov 2006 11:30:34 -0800
Message-ID: <1163100632.278935.65480_at_b28g2000cwb.googlegroups.com>
Tchuzhie Giri wrote:
> It is not "OK" so long as one does not have your rules of updatability.
> You put a pile of symbols on the pile of symbols: it does not have
> sense without the rules. Please provide the rules, simple examples
> and then one can go to more complex examples.
Given two relation variables
Y(n, #) -- aka WorkPhones(name, number)
and
Z(n, #) -- aka CellPhones(name, number)
and two relation constants
A = {(t='work')}
and
B = {(t='cell')}
is the view
X = (Y /\ A) \/ (Z /\ B) -- aka ConsolidatedPhones
updateable? There is no minus operator involved. The only two RA operators are join /\ and union \/. Received on Thu Nov 09 2006 - 20:30:34 CET