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:[EMAIL PROTECTED]] > 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. > [EMAIL PROTECTED] > > -----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: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: DENNIS WILLIAMS > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: Alexandre Gorbatchev > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > ********************************************************************* This e-mail message, and any files transmitted with it, are confidential and intended solely for the use of the addressee. 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