Re: Doohickey to visually show relationships between files

[Vern Hamberg <vhamberg@xxxxxxxxxxxxxxxxxxxxxxxxx>]

You can't document what you don't have. There are already the means to set 
up all these relationships - it's called referential integrity. Set up 
foreign keys in order to get the relationships.

Does any RDBMS let you put things like 1-to-n and n-to-1, etc., into the 
definition of a schema? Are there any that enforce those kinds of things? 
If so, great.

Some of what you want is already here -- use it!

But putting RI into things has implications for performance and changes in 
applications. RI will generate messages you need to handle, it'll actually 
DO things you used to do in code, etc. And every constraint is actually 
maintained as an additional access path, so performance could have a hit.

;-)
Vern

At 04:51 PM 6/30/2004, you wrote:
> In a message dated 6/30/2004 5:15:27 PM Eastern Daylight Time,
> WaldenL@xxxxxxxxxxxxxxx writes:
> > Jack,
> >
> > DSPFD, DSPFFD and DSPDBR are all fine and dandy when you want to know
> > something about a single table, but when you want to know about the
> > relationships _between_ tables, you need something more.
> >
> > Perhaps you can keep all the relationships in you head, but on systems
> > with several thousand tables I know I don't recall them all. To be able
> > to select a single table and see all the "related" tables is invaluable.
> > Add to that the ability to select table A and table F and visually see
> > the way to get from A to F is great!
> >
> > DSPFD, FFD and DBR are great tools, but the world has evolved, it's time
> > for the iSeries community to do the same.
> >
> Walden,
> You are 100% correct with regards to the iSeries needing to evolve but I
> think the members of our community would get more results aiming there 
> efforts at
> IBM to make them require or better allow for any file relationships to be
> defined within the context of the DDS or now the SQL definitions rather then
> leaping onto the Microsoft band wagon to solve our problems.
>
> The concepts of a schema have been around for a very long time so all we have
> got to do together is push IBM off of the "seat down the hall"
>
> Jack Derham
> Direct Systems, Inc.
> Marietta, GA