Re: Should an application ever be allowed to change a schema?
Date: 17 Apr 2004 11:34:52 -0700
mAsterdam <mAsterdam_at_vrijdag.org> wrote in message news:<40812411$0$561$e4fe514c_at_news.xs4all.nl>...
> Karen Sundquist wrote:
> > Imagine a database that is only accessed by a server application.
> (Sorry for being slightly off-topic.
> I am trying to initiate a c.d.theory glossary.)
> This effectively reduces the meaning of the word 'database' to
> 'deluxe filesystem'. No problem, many use the word in that sense.
> The implication it is that part of the server application may be
> busy taking care of contraints which would have to be guarded by the
> dbms if there would be other applications. Typically, developers
> *will* implement some of the more complicated contraints in
> the server application. This severely limits the chance of the
> data ever being shared. 'Import' and 'export' facilities
> become crucial to the success of the application.
I don't understand your deduction that a database accessed only by server applications is no longer a database or that constraints cannot be included is such a database. Is it because, the actual users are hidden from the database, so user level privileges must be looked after by the application?
As you know, many databases these days are accessed directly only by the superuser and by a number of middleware server applications that marshal end user queries. Data is shared by these separate applications. Critical constraints are included in the database that are common to all users of the data. The middleware applications may impose their own local constraints which are not critical to the integrity of the data.
Karen Received on Sat Apr 17 2004 - 20:34:52 CEST