Re: On the subject of Data Warehouses, Data Cubes & OLAP....

"DataMan" <dataman_at_ev1.net> wrote in message news:vpdppi7ccdn0f1_at_corp.supernews.com...
>
> "Bob Badour" <bbadour_at_golden.net> wrote:
> >"DataMan" <dataman_at_ev1.net> wrote in message
> >news:vpdad0mimma52e_at_corp.supernews.com...
> >>
> >> Most OLTP systems do support the information requested. It's just very
 difficult
> >> to retrieve.
> >
> >That is a remarkable and very interesting assertion. What can you offer
 to
> >support such a remarkable assertion?
> >
> The support information or difficult to retrieve statement?

I do not find the "support information" assertion remarkable, and I doubt anyone would. What can you offer to support your remarkable assertion that information is difficult to retrieve?

> >> Additionally when the business requires enterprise level reporting
> >> across the various functional applications, a warehouse becomes a
 necessity.
> >> You know the scene, large company with 10 different order entry systems
> >> for each functional area of the company (i.e. cost center). One for
 small
> >> biz, one for consumer, one for z product, one for y product, etc. And
 of
> >> course there was never any upfront effort by a data management
 organization
> >> to ensure consistent representation of enterprise level entities. So
 you
> >> end up with a hodge podge set of data that must be abstracted to make
 consistent
> >> within a DW environment. And since you're already there go ahead and
 put
> >> it in a dimensional format so somebody can understand it and easily
 pull
> >> data/reports.
> >
> >What exactly is a dimensional format? How does it differ from >relational
> representation?
> They are both relational. Assuming both the application database and the
> data warehouse are both stored in relational databases. Was your question
> directed to differences between a data warehouse database (let's say OLAP
> for convenience) and an application database (let's say OLTP for
 convenience)?
> The primary difference is purpose. OLTP must support consistent real
 time
> data. OLAP only need support historical reporting.

So then, OLAP is just another word for "snapshot" as in "a derived stored relation" ?

> >How or why can it improve understanding? How have you measured >this
 improved
> understanding?
> I didn't say that it does.

"And since you're already there go ahead and put it in a dimensional format so somebody can understand it and easily pull data/reports."

It sounds to me like you did. If you did not say that, what the hell did you intend to say?

> >What features does it provide that facilitate reporting?
> >
> The data structure allows for easier retrieval.

Since the logical data structure is a relation in both cases, I fail to see how it alters anything with respect to retrieval. Perhaps you would like to clarify your remarkable statement? Received on Wed Oct 22 2003 - 23:21:34 CEST