Argument for 1NF by counter-example
From: Kenneth Downs <firstinit.lastname_at_lastnameplusfam.net>
Date: Sat, 23 Oct 2004 20:57:44 -0400
Message-ID: <emuelc.ivc.ln_at_mercury.downsfam.net>
Have been following these conversations on 1NF, atomicity, types vs. relational and so forth. Very good reading overall.
Date: Sat, 23 Oct 2004 20:57:44 -0400
Message-ID: <emuelc.ivc.ln_at_mercury.downsfam.net>
Have been following these conversations on 1NF, atomicity, types vs. relational and so forth. Very good reading overall.
I have an example from real life that seems to suggest Codd's original 1NF is not ready for the grave just yet.
A colleague of mine wrote a report writer. Each report was stored in a single row in a table. The table had plenty of type 'text' columns (clob's in some dialects) that contained comma-separated lists. One list of columns, a list of the order-by columns, a list of the group-by columns, and so forth. Each new feature tended to lead to another text column and another comma-separated list.
-- Kenneth Downs Use first initial plus last name at last name plus literal "fam.net" to email meReceived on Sun Oct 24 2004 - 02:57:44 CEST