Re: the relational model of data objects *and* program objects
Date: 19 Apr 2005 06:41:05 -0700
Message-ID: <1113918065.312217.150560_at_z14g2000cwz.googlegroups.com>
Alexandr Savinov wrote:
> The relational model does not have hierarchies and it is obviously a
> serious drawback (one of many, actually). The worst problem however
is
> that the relational model does not want to have hierarchies because
this
> theory is in a frozen state and simply does not recognize that there
> could be any problems in use of this model.
See http://www.dbdebunk.com/page/page/1490192.htm
> Having hierarchies is only one thread leading to a new model. Indeed,
> why we have to store (to model) all our tables in one space/scope? We
> never do it with our own files or other things so why do we do it
with
> tables? Because there are no other means.
You are confusing logical and physical. Relational tables (relations) don't specify where they are stored, nor whether a given table is stored in one place or many. A single (logical) relation might be implemented by physical storage scattered across many locations - or not. The user doesn't need to know either way.
Don't confuse a few current SQL DBMSs with "the relational model", and come to the erroneous conclusion that a new model is needed! Received on Tue Apr 19 2005 - 15:41:05 CEST