Re: Counting propositions
Date: Tue, 15 Jun 2004 12:26:38 -0500
"Laconic2" <laconic2_at_comcast.net> wrote in message
> "Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote in
> > I suspect most designers would suggest that if you have the information
> > which the aggregate is based, then you put that into a base relation and
> > aggregate from the granular data. But there are so many exceptions to
> > in actual use.
> You might want to look over Kimball's book on warehousing. He writes a
> on "choosing the granularity". It's fairly crucial in MDDB design.
I've got it on the shelf and read it a while back, but what interests me more is when OLTP implementations (rather than OLAP or data marts/warehouses) track data at an aggregate level. I think my interest is tied to the question of why 1NF (a means of not aggregating) is considered self-evident to some, even some who then aggregate by use of attribute such as quantity. The connection isn't obvious, or possibly even there, but that's where my head was with that question. Cheers! --dawn Received on Tue Jun 15 2004 - 19:26:38 CEST