RE: Warehouse design: snowflake vs star schemas

No no - it wasn't to do with the specifics of snowstorms or cosmic radiation, rather a further discussion of the issues of database design, which ultimately has to be the reference point in any discussion of star schemas etc.

peter

> -----Original Message-----
> From: DENNIS WILLIAMS [mailto:DWILLIAMS_at_LIFETOUCH.COM]
> Sent: 14 October 2002 15:09
> To: Multiple recipients of list ORACLE-L
> Subject: RE: Warehouse design: snowflake vs star schemas
>
>
> Peter - What does this article have to do with snowflake vs.
> star schema? I
> didn't see where Chris Date was advocating snowflaking.
>
> Dennis Williams
> DBA
> Lifetouch, Inc.
> dwilliams_at_lifetouch.com
>
> -----Original Message-----
> Sent: Monday, October 14, 2002 4:59 AM
> To: Multiple recipients of list ORACLE-L
>
>
> Just for the record (and perhaps to confirm that there are
> always two sides
> to a story). Readers may like to see the article Chris Date
> wrote to Ralph
> Kemball on the subject of business rules and integrity constraints:
>
> http://www.dbdebunk.com/kimball1.htm
>
> peter
> edinburgh
>
>
> > -----Original Message-----
> > From: Alexandre Gorbatchev [mailto:alexandre.gorbatchev_at_avermann.de]
> > Sent: 09 October 2002 15:04
> > To: Multiple recipients of list ORACLE-L
> > Subject: RE: Warehouse design: snowflake vs star schemas
> >
> >
> > Dennis,
> >
> > Thanks for the link. It's a great DW resource.
> > There are not only fundamentals, but some valuable real-life
> > stuff, which is
> > what I need. Live and learn, learn,learn...
> >
> > Regards,
> > Alex
> >
> > -----Original Message-----
> > WILLIAMS
> > Sent: Tuesday, October 08, 2002 7:39 PM
> > To: Multiple recipients of list ORACLE-L
> >
> >
> > Alexandre
> > Stephane gave you an excellent reply. If you want to learn
> > more about
> > these DW design issues, I would start by visiting
> > http://www.ralphkimball.com. He is one of the leading figures
> > in the DW
> > field, and has copies of all his articles posted on his site.
> > I would start
> > with the oldest articles because those are where he discusses the
> > fundamentals of data warehousing.
> >
> >
> > Dennis Williams
> > DBA
> > Lifetouch, Inc.
> > dwilliams_at_lifetouch.com
> >
> > -----Original Message-----
> > Sent: Tuesday, October 08, 2002 3:29 AM
> > To: Multiple recipients of list ORACLE-L
> >
> >
> > Stéphane,
> >
> > Thanks for response.
> >
> > > I have always discplined myself to use star schema and
> > > never snowflake.
> > Would you mind asking why?
> >
> > > The "Which one is easier to implement and easier ETL
> > > ?" is not a good question as your data model should
> > > not be design for the ETL procecess but only for the
> > > querying.
> > I mean ETL to load data _INTO_ data warehouse. Of course,
> > complexity is
> > mostly determined by sources, but still I'd like to know if
> > there is any
> > general influence by DW's data model.
> >
> > Another question. Is it feasible to make date dimension or
> > just use date
> > column? For example, Oracle Discoverer can work with date
> > columns using
> > hierarchies Y->M->D and similar.
> > What is faster: separate table for date dimension or date column?
> > If I go with date dimension table should I use date column as
> > a foreign key
> > in fact table or use some artificial key?
> >
> > TIA,
> > Alexandre
> >
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > --
> > Author: Alexandre Gorbatchev
> > INET: alexandre.gorbatchev_at_avermann.de
> >
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> Author: Robson, Peter
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