Re: Pizza Example

From: Tony <andrewst_at_onetel.net.uk>
Date: 6 Apr 2004 14:28:53 -0700
Message-ID: <c0e3f26e.0404061328.548abd4e_at_posting.google.com>


Jerry Gitomer <jgitomer_at_erols.com> wrote in message news:<pan.2004.04.06.14.19.44.379230_at_erols.com>...
> On Tue, 06 Apr 2004 05:01:24 -0700, Tony wrote:
>
> > Jerry Gitomer <jgitomer_at_erols.com> wrote in message
> > news:<pan.2004.04.06.05.00.25.384317_at_erols.com>...
> >> On Mon, 05 Apr 2004 11:19:56 -0500, Dawn M. Wolthuis wrote:
> >>
> >>
> >> [snip]
> >> > What I have seen with RDBMS's is that the size constraint is placed on
> >> > everything while more important constraints related to the allowable
> >> > values are not as often applied, especially when it is a "yellow flag"
> >> > type of data value for an attribute rather than obviously not
> >> > permitted. I'll put this in a separate thread at some point (but have
> >> > several other questions prior to that one).
> >> >
> >> >
> >> I prefer that the "more important constraints" be handled by the
> >> application programs rather than incorporated into the RDBMS. This is
> >> because the application programs are specified and written by developers
> >> and analysts who are working with the users and have first hand
> >> knowledge of the business rules while the database is cared for by the
> >> DBAs who are concerned with the efficiency and effectiveness of the
> >> database in meeting the needs of many different applications.
> >
> > I was agreeing with your post right up to this bit. Yes, the database is
> > cared for by DBAs, but the constraints are specified by analysts and
> > written by database designers (who may or may not also be the DBAs). The
> > very fact that the database meets the needs of many applications is the
> > reason for handling "more important constraints" (especially) in the DBMS.
> > Otherwise the DBMS is just a glorified file system, not a Database
> > Management System.
> >
>
> We disagree on this point. My own opinion is based on my experience where
> I was responsible for 12 production databases supporting literally
> thousands of application programs. Neither I nor my junior DBAs had the
> time to become familiar with the requirements of the various applications
> we were supporting. Under these conditions I felt that it was necessary
> for the analysts and developers doing the applications to design and
> implement the validation procedures in their programs. My understanding
> with the analysts and developers was that if they gave me good data to
> store in the database I would guarantee that it stayed good and would be
> available without change or modification until scheduled for deletion.

That's fine - you are DBAs, and your focus is on supporting the database. But between the DBAs and the application programmers there should be a third role - possibly overlapping, possibly not: database designer. The database designer, not the DBA as such, should be responsible for defining the appropriate database constraints. The responsibility for stored procedures falls into another gap, somewhere between the front-end application code and the database. Not all DBAs can write good stored procedures, though of course many can; nor can all user-interface coders write good stored procedures - it is a different skill set. Received on Tue Apr 06 2004 - 23:28:53 CEST

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