Re: foundations of relational theory?
Date: Sun, 02 Nov 2003 17:39:31 -0500
Message-ID: <3551203.1067812771_at_dbforums.com>
>
> Basically:
> * Structure:
> All data in D3 is stored as items within files.
> Items within these files are divided into sets called attributes which
> contain one, multiple, or no values.
> * Integrity
> Can be enforced in multitudinous ways. It is perhaps worth noting that
> much of what is elsewhere called "data integrity" falls (quite rightly
> imo) under the heading of "input validation" in Pick applications that
> run wholly or partly within the DBMS. Pick has full ACID compliance
> for transaction handling btw.
> * Manipulation
> What is there to say? You read, write & delete data as you need to -
> and you need to do much less of it in Pick than with any of the
> attempts to implement the relational model.
>
> If you want, as I suspect you might, more in-depth answers then can
> you point me to a definition of a model with these sub-headings that I
> can use as a kind of template?
>
Here is the relational models conformance to a definition of a data model.
Its general theory is set theory and predicate logic expressed as...
- Structure - R-tables
- Integrity - Domain, attribute, relation, database
- Manipulation - R-operations (R-algebra & R-calculus)
-- Posted via http://dbforums.comReceived on Sun Nov 02 2003 - 23:39:31 CET