Re: Why using "Group By"
Date: Thu, 13 Mar 2003 13:36:07 -0800
"Bob Badour" <bbadour_at_golden.net> wrote in message
> I am unfamiliar with the proposal you mention, but that is not the result
> recall getting in any case.
> > For syntactically correct "group by" (when the select column list is a
> > subset of "group by" list) rewritten the results are identical.
> Except that the only purpose of this is to destroy logical identity. Is
> as good as maintaining logical identity? I think not.
What is logical identity, that you refer to so often? Do you mean that a relation where we have employee name in the first column, and the sum of all salaries -- a constant -- in the second column would be a semantically invalid proposition? Received on Thu Mar 13 2003 - 22:36:07 CET