Talk:Relational Model/Tasmania

Change of Codd's RDBMS Rule after research
Dear Sir,

Myself, Shekhar P. Sinha, have found that in " RDBMS-Oracle according to Codd's Rule only a single primary key can be defined in a single table " but " I have found that " I can define more than one primary key in RDBMS-Oracle single table" and this was successfully done on 4th of July, Saturday, 2009 I would like to have your suggestion.

Thanking you Sir, with regards,

Shekhar P. Sinha, iFuture College of Technology and Mgmt.


 * Hi Shenkhar - I'm not sure what this question has to do with the RM/T model specifically. Perhaps you should post this in the discussion board for RDBMS databases instead. It does seem odd to have two primary keys for a single table - a contradition in terms if nothing else, since there cannot be two primary things can there? Certainly it is acceptable to have a Primary key and several other Candiate keys. One thing to note - please don't confuse the way database vendors like Oracle, Microsoft or IBM implement the relational data model and the SQL standards are also an imperfect implementation of that model. C. J. Date has written extensively about the problems with the SQL language and has even invented his own query language, Tutorial D, to help improve matters. Egrabczewski (talk)