Re: A neutral challenge.

"Bob Badour" <bbadour_at_golden.net> wrote in message news:cd3b3cf.0306280919.7a6ab963_at_posting.google.com... > "Isaac Blank" <izblank_at_yahoo.com> wrote in message news:<HSZKa.761$Ks2.68590664_at_newssvr15.news.prodigy.com>...
> > "Bob Badour" <bbadour_at_golden.net> wrote in message
> > news:UYLKa.588$Sp2.78550140_at_mantis.golden.net...
> > > "Peter Koch Larsen" <pkl_at_mailme.dk> wrote in message
> > > news:61c84197.0306261140.6454f73c_at_posting.google.com...

> > > > Ideally, my belief is that the granularity should be arbitrarily
small
> > > > - this will make the solution applicable for other jinds of
schedules
> > > > as well. If you do choose a specific interval this should be
allowed,
> > > > but in that case I would expect some explanation as to why this
> > > > specific interval was chosen.
> > > >
> > >
> > > I don't think it makes sense to schedule rooms to the nanosecond. To
the
> > > quarter-hour is probably as great a granularity as anyone would ever
> > really
> > > use in practice and to the minute should provide a safe enough margin
of
> > > over engineering.
> > >
> > Ideally, the database layer should be able to handle any reasonable
> > granularity and let the front end restrict it to whatever the policies
are.

>
> I explained above why 1 minute granularity is reasonable for
> scheduling rooms. Why do you think the dbms should ignore systemic
> constraints allowing applications to enforce them instead? That seems
> to contradict almost every principle of good database management.

    For one thing, Peter's reasoning does have its merit - you could easily re-use the same desiign and code for another scheduling application.

    Also, imposing this limitation would probably make the database design and code more complex than it should be. I can easily come up with a simple and fast database design using native SQL types for timestamps, but enforcing the granularity by means of appropriate database schema and constarints will be a little bit challenging. So if someone wanted me to enforce the granularity of 1 minute with the database native granularity, say, 1 second, I would rather enforce this by checking parameters of the stored procedures used to communicate between the front ent part of the application and the database. Received on Mon Jun 30 2003 - 17:30:53 CEST