Re: codd's 12 Rules

The real problem is, many older applications use DDS and were designed as essentially 'flat file" databases, that are not truly "relational" (repeating fields or an array stored in a single large field, for example... or a file that has different record "layouts" depending on some code in a certain position in the record, etc.)

Especially many older applications "ported" toOS/400 (or IBM i) from e.g. System/36 SSP ... =-O

So, while the platform may be capable of supporting those rules, the platform does nothing to force you to write applications that conform to those rules. And there's the rub.

And we all know how few of the many applications vendors on IBM i really ever bother to convert from e.g. RPG/400 to ILE RPG IV, let alone convert from DDS to SQL DDL and truly take advantage of "relational integrity" with constraints, rules and triggers, etc. :-\

Just sayin'...

Mark S. Waterbury

> On 5/17/2013 2:49 PM, DrFranken wrote:

I dunno, I read those rules and it seems that 9,10,11,12 all are
supportable on IBM i. Need someone more smarterer on the DB than me....

- Larry "DrFranken" Bolhuis

www.frankeni.com
www.iDevCloud.com
www.iInTheCloud.com

On 5/17/2013 2:43 PM, Charles Wilt wrote:

I seem to recall hearing that no current RDBMS meets all of Codd's rules..

http://www.cse.ohio-state.edu/~sgomori/570/coddsrules.html

"Note that based on these rules there is no fully relational database
management system available today. In particular, rules 6, 9, 10, 11 and 12
are difficult to satisfy."

Charles


On Fri, May 17, 2013 at 2:29 PM, Nathan Andelin <nandelin@xxxxxxxxx> wrote:

Does AS/400 follows all 12 codd's rules.

Yes, Absolutely. Unequivocally.

-Nathan

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