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Is Oracle Supports all 12 rules of Dr .Ef Ted Codd

624846Feb 23 2008 — edited Feb 24 2008
Hi Fellows,

I am Asif and I what to discuss something with you all.

Dr. E.F. Codd, an IBM researcher, first developed the relational data model in 1970. In 1985, Dr. Codd published a list of 12 rules that concisely define an ideal relational database, which have provided a guideline for the design of all relational database systems ever since. 
you can visit this link to study those rules...

http://www.itworld.com/nl/db_mgr/05072001/

According to Dr. E.F. Codd, the software who support all those 12 rules will be called a full relational database management system.

Is Oracle's new version support all those 12 rules or not?


Many Thanks

Asif Javaid Chughtai.
Software Engineer
eVenture Solutions
Lahore Pakistan

Comments

ajallen
Start with the Oracle concepts guide and see how many of these questions you can answer for yourself from that reading.
591309
see this
108476
Hi,
a list of 12 rules that concisely define an ideal relational database
Note the word "ideal".

Can Oracle be configured to meet the rules? Yes.

Does Oracle have a zillion extensions that violate it? (IOT's, sorted hash clusters, VARRAY columns). Yes.

Chris Date has defended these rules, and it's clear that practice separates from theory:

http://www.dba-oracle.com/oracle_news/news_chris_date_interview.htm

HTH. . . .

Donald K. Burleson
Oracle Press author
Hans Forbrich
Why did you stop your cut and paste with the first paragraph ? The second paragraph starts with

"I use the term "guideline" because, to date, no commercial relational database system fully conforms to all 12 rules. "

As I understand it, the SQL language itself does not actually allow full conformance.
Eduardo Legatti
Hi,

>>Is Oracle's new version support all those 12 rules or not?
Nowadays, I'm not sure about the rule 10 (Integrity Independence) ...

"Rule 10: Integrity Independence
The database language (like SQL) should support constraints on user input that maintain database integrity. This rule is not fully implemented by most major vendors. At a minimum, all databases do preserve two constraints through SQL.

* No component of a primary key can have a null value. (see rule 3)
* [url http://forums.oracle.com/forums/thread.jspa?threadID=617660&start=0&tstart=0]If a foreign key is defined in one table, any value in it must exist as a primary key in another table."

Cheers

Legatti
Niall Litchfield
Hi,
a list of 12 rules that concisely define an ideal
relational database

Note the word "ideal".

Can Oracle be configured to meet the rules? Yes.
I disagree with this, though not the real-world vs theory thrust of your post.

Codd's Rule 3 would seem to rule out the use of the empty string to represent null strings.

I seem to recall that Oracle can't implement all integrity constraints declaratively (separately from app code) but that may not be in Codd's rules

Niall Litchfield
http://www.orawin.info
damorgan
The rules are here:
http://www.psoug.org/reference/codds_rules.html
Niall Litchfield
The rules are here:
http://www.psoug.org/reference/codds_rules.html
Yes, and in the original link as well. My memory - but it may be from other work though notably Toon (and Lex's work) eg http://web.inter.nl.net/users/T.Koppelaars/AM4DP_Part1.ppt (and Part2 obviously) - is that relational theory contains more required integrity constraints than those implemented declaratively in Oracle (and other dbms). rule 10 doesn't specify what is meant by integrity constraint.

Niall
108476
Hi Niall,
I disagree with this, though not the real-world vs theory thrust of your post.
Fair enough, we must remember that relational theory is just that; theory, and the "ideal" may never be pragmatic.

The one that gets me is that the underlying data structure does not matter . . . . .

I remember that the highlight of Database World was to watch Chris get bent out of shape when Dr. Kim came out with his 0NF DB (UniSQL).

He got so mad that the veins on his forehead popped out! But he did revise his definition of a "set" because of it . . . .
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