Re: The sixth normal form is just a name - nothing more.

Op vrijdag 3 augustus 2018 22:47:15 UTC+2 schreef vldm10:
> The authors of 6NF have not constructed a procedure that will decompose any
> relation into corresponding set of binary relations. The binary relations
> consists of a simple key and an attribute.
>
> Authors of 6NF, in all examples use only relations that contain a simple key.
> The simple key is the simplest form of the key. They do not mention the
> complex key, which is the most important case for keys.
>
> Here, I think on the following book: Temporal Data & the Relational Model"
> from 2003, by Date, C.J .; Darwen, Hugh; Lorentzos, Nikos. In this book is
> presented 6NF.
>
> The reason for this bluffing is that these authors can not solve the history
> of events and can not construct atomic structures for corresponding complex
> relations. They also can not solve entire parts of database practice(regarding
> history and atomic structures).
>
> Vladimir Odrljin

I picked the book and the second random page I grabbed (184, FWIW) had the following example :

SP_SINCE { s# , p# , SINCE } KEY { s# , p# } SP_DURING { s# , p# , DURING} KEY { s# , p# , DURING}

You need to improve on your fact-checking. Received on Wed Oct 03 2018 - 22:44:37 CEST