Re: sql views for denomalizing

Marshall Spight wrote:
> Lauri wrote:
> >
> > I still think it would be advandageous for the
> > discussion in hand if you could just create a 3-file minisystem and
> > give a couple of queries. It does not have to be syntactically correct
> > and you can even use pseudo code if you want. I think that here 20 rows
> > of code easily equals 1000 words of explanation.
>
> Yes! That would be great.

It's now on my to-do list and I will either get to it this week, or, more likely, after I switch from mostly talking/reflecting back to hands-on this Fall.

> Also interesting would be a discussion of the change management
> features. Pick people are often bragging about change management,
> particularly cardinality changes of fields.

You can change a metadata attribute from describing a value as single or multivalued with a single simple change to a dictionary for a file.  If you have an attribute of "genre" in a media file/relation and you later determine that you need multivalues rather than a single value for this attribute, then you can flip that attribute to multivalued (from SV to MV, for example). Nothing needs to be done to any files themselves, only to the description of such.

Depending on your development and run-environments, in theory (not typically in practice), the "data entry screens" could now adjust automatically from a single entry field to have a scroll bar and take in multiple values. Similarly, and more likely, reports will simply list the multiple values under each other in the same column of a report. Other aspects of an application would need to adjust the logic accordingly (e.g. paper-based forms would need to have space for additional values, for example).
--dawn

> Marshall
Received on Mon Aug 01 2005 - 20:35:57 CEST