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

Gene Wirchenko wrote:
> On Tue, 07 Jun 2005 16:43:32 +0100, Paul <paul_at_test.com> wrote:
>
> [snip]
>
> >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.
>
> I really wonder about that. The XML bandwagon is one of my
> concerns.

It's especially bad because XML attracts the many developers who seem to have no knowledge of SQL (much less relational). Why, I don't know... having worked with DBMSs and XML, doing both manual "mapping" code (JDBC/SAX/DOM) and "mapping frameworks" (Hibernate/Digester/JAXB), there's really no benefit whatsoever to XML in that regard. And its problems are described well elsewhere.

Frankly, no JDBC code, however poor, can ever match the horrors of traversing an XML tree. Even bad JDBC can be refactored fairly easily; untangling XML manipulation code should have been another labor of Hercules. I'd rather clean out the stable.

> >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.
>
> You mean when computers were used in the effort to send men to
> the moon?

Excellent!

• erk