Re: Poll: What percentage advantage are RDBMS vendors taking of the RM?

"Paul" <paul_at_test.com> wrote in message news:42a5c0a5$0$41896$ed2619ec_at_ptn-nntp-reader03.plus.net...
> mountain man wrote:
>> What I am trying to ask is "How *relational* are DB2, Oracle and SQL
>> Server
>> according to the principles of the relational model?
>>
>> People assert that these SQL-DBMS are "the best we have at the moment"
>> and that they are not ("Fully") relational. I want to understand just
>> HOW
>> MUCH they are not fully relational, as a ball-park rough-as-guts
>> estimate.
>>
>> Is it 10% or is it 90%. ?
>
> Well here's a list of Codd's 12 rules, which are general guidelines for
> a DBMS to be thought of as relational:
>
> http://www.wildewood.co.uk/comp/more/codds_rules.html
>
> I'd say most SQL-DBMSs are inspired by this, although some of the rules
> clearly aren't followed. But we're getting there slowly.
>
> It's easy to criticise DBMS designers for not building a
> fully-relational product, but I think the practical problems are bigger
> than we might think. It's a serious level of abstraction, especially
> when you consider that many DBMSs were started years ago when computer
> were many orders of magnitude less powerful than they are today.
>
> I'll give them 8 out of 10 for effort. :)

Thanks for the "quantification".
So we have two 8's, a 4 (Alfredo)
and alot of nulls.

-- 
Pete Brown
IT Managers & Engineers
Falls Creek
Australia
www.mountainman.com.au