Oracle does not allow several key primary why...?

Hi gurus,

Why oracle does not allow for multiple primary keys in a table...

Although people said not null unique primary key = + (it is possible for the other columns when creating)

Instead, oracle can define multiple primary keys... right...

CANY comments please or any specific reasons please

Thank you
Prasanth

It is called composite primary key. Primary key is one, but which consists of the combination of several columns. The AskTom link will show you why the primary key is not equal to NULL UK + OT.
http://asktom.Oracle.com/pls/Apex/f?p=100:11:0:P11_QUESTION_ID:8743855576462
These thoughtfully red links
http://download.Oracle.com/docs/CD/E11882_01/server.112/e16508/datainte.htm#CHDDBJBB

In addition, you can know the Codd rule:
http://en.Wikipedia.org/wiki/Codd%27s_12_rules
http://www.Oracle-DBA-online.com/SQL/Codd_rules.htm

Tags: Database

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