Re: MV Keys
Date: Sat, 04 Mar 2006 00:27:47 +0100
Message-ID: <bdjh02hungkntvi4il3b5nnv31gc0ktdeb_at_4ax.com>
On 3 Mar 2006 05:49:52 -0800, "dawn" <dawnwolthuis_at_gmail.com> wrote:
>This issue of minimizing complexity is confusing. A logical data model
>is implemented by developers using an interface to a dbms. There are
>trade-offs in any design, of course, and if we are going to build a
>house with round walls it will cost additional dollars. But we don't
>want dbms tool designers to suggest they will be making design
>decisions based on simplifying the design for the computer or for the
>dbms developers. The simplicity we need to care about a bit more is
>the simplicity for the user of the tools. I think that is where
>Marshall's use of the term "power" comes in. Surely you can implement
>a list, for example, using the RM, but the tool is not doing much work
>for you. It doesn't have enough power. It isn't simple enough from a
>user standpoint.
The RM ("relational model") is not a tool -- it is a model, just as the name says it is. Of course, the finest database does nothing until some application *uses* it. The fact that applications can reside in the database itself in the form of scheduled jobs which run stored procedures, etc. shouldn't blur the distinction between the two ("application != database" ... say this 120 times every day when you get up in the morning, then maybe you will see things a little clearer).
The RM is a model for storage and manipulation of data which can be used by very many different applications, and the applications need not know anything about each other. That is the beauty, and the strength, of the concept. It is up to the application to provide an interface to the user which is easy to use; this shouldn't be a requirement of the database! In most respects, the duty of a good database design is to *protect the data* from abuse by misinformed users (and I include application developers here as well).
A good database design is usually never "simple enough" to the average user. But it really doesn't matter because "simple" shouldn't be a requirement for database design. At best, it might serve as a requirement for a user interface design.
-- Bob Hairgrove NoSpamPlease_at_Home.comReceived on Sat Mar 04 2006 - 00:27:47 CET