Re: foundations of relational theory? - some references for the truly starving
Date: Wed, 22 Oct 2003 13:42:57 +1000
Message-ID: <3f95fcef$0$95044$c30e37c6_at_lon-reader.news.telstra.net>
>The basis in facts are very simple: Nested Relations offer no extra
>expressive power, and plenty of complications.
I agree they add no expressive power: converting a 3NF to a 1NF structure
will give you the same expressive power. Could you expand on your "plenty of
complications".
The pick model allows the "clustering of precomputed joins" by the programmer. And modern variants (like UniVerse which is the one I work on). Allow you to use SQL queries against this clustered and precomputed data (it can also use other pick style languages and methodologies but that is beside this point).
UniVerse also allows you to apply strict typing to columns as per SQL 92
(although this is an extension of Pick)..
>It is you who should give me a good reference -- not marketing idiocies
Craig
>about how "joins are difficult to compute" --, that you consider
>relevant for showing the difference. And we'll see.
Perhaps Mike mean't that joins can be *EXPENSIVE* rather than difficult to
compute.