Re: What is this model technique called

From: Kenneth Downs <ken_remove_underscores_downs_at_downsfam.net>
Date: Sun, 08 Jun 2003 10:34:17 -0400
Message-ID: <9hhvbb.h34.ln@mercury.downsfam.net>

Quoting unnamed sources, Abdullah Kauchali claimed:

>> What the heck is a "spill-over attribute"?  This sounds like you mean
>> "a bad design" and you ned to do some research.  \

>
> I am not advocating EAV as a first-design approach. I'll go further - I
> don't think the "E" part of EAV is a good idea either. But I will, and
> have used, the "attribute-value" [if there is such a concept?! :-))]
> generic model for those tables where attributes are virtually impossible
> to foresee
> at analysis/design time. So, in such cases, I would model the correct
> table and try my best to get a concrete set of attributes - but as a
> production-stopage risk mitigating design, I would hook off the "AV"
> (that's EAV - E) design for some "risky" tables.
>
> Only as an exception. [Here we can accept poor performance because of the
> design, but in the mean time our production uptime is 100%.]
>

>>>These are attributes, not wine.

> LOL!
>

>>>And columns are not fields.

> why not? [I thought the industry uses these terms interchanageably?]
>
> regards
>
> Abdullah

Mr. Celko's suggestion would eliminate the need to do this, if the tools provided for very fast idea-to-code. The EAV idea seems to be under active discussion at the moment, and "andrewst" put it best in this very thread with:

"I think every database designer/developer goes through a stage where they think 'Hey, I can generalize this down to 2-3 tables: entities, attributes and (maybe) relationships. What a super-flexible solution!'"

He then points out that those of us who have tried it realize we must go piece by piece through the DB Server and re-implement every single feature, since the system is meant to work on predefined columns inside of tables.

It is much simpler, easier, and effective to have a set of tools that lets you rapidly react to design changes.

-- 
Kenneth Downs

Received on Sun Jun 08 2003 - 09:34:17 CDT