Re: An object-oriented network DBMS from relational DBMS point of view
Date: Wed, 14 Mar 2007 18:09:10 GMT
On Tue, 13 Mar 2007 17:23:30 +0100, Alexandr Savinov <spam_at_host.com> wrote:
>> On 12 Mar 2007 10:43:17 -0700, "Dmitry Shuklin" <shuklin_at_bk.ru> wrote:
>>>> That's not news, that an unconstrained description has constrained
>>>> grammers as a subset, that type 0 grammar has type 1,2,3 grammars as
>>>> "special cases", but the general case does not have some of the
>>>> properties of its simplified, special cases.
>>> Agree. But if some system allows to implement type 0 grammar then also
>>> it allow implement constrants and emulate type 1,2,3 grammars but not
>>> vice versa.
>> Well, I don't know.
>> The value of an RDBMS is that it holds ALL the data.
>Any system exists in some *context* (meta level, environment etc.) which
>influences in one or another way its behavior and semantics. So it is
>not possible to hold ALL the data independent of what kind of DBMS you use.
I clarified this for Bob, ALL doesn't mean all in the world, it means through some unified model, which RDBMS provides and any heterogenous mechanism denies. It's not a matter of context, the whole point of any computing system is what can be done "context-free", as we used to say. In computing, context is a dividing line, fortunately, or we'd be stuck trying to put the whole universe into every program.
Yeah, I know this conflicts with what you thought, but give it a whirl and see if it isn't actually right.
J. Received on Wed Mar 14 2007 - 19:09:10 CET