One philosophy of DW states that you build a DW that is
fairly normalized, much like an OLTP database, albeit one
with a temporal component and complete logging of transactions
within the data.
This is then used as a warehouse. The data from the DW is used
to assemble data marts. These data marts are queried by users.
They never look at the data warehouse.
So to answer your question: It depends.
* On how much time you have
* do you want the ability to create new data marts without adding to
the ETL system ? ( it should already be getting everything you need )
Since you already have something that looks like a DW, why not
use that to build data marts that employ star schemas and bitmap
indexes? They are easier to query, and faster.
I believe both Kimball and Inmon subscribe to this philosphy.
Jared
Gurelei <[EMAIL PROTECTED]>
Sent by: [EMAIL PROTECTED]
05/10/2002 11:43 AM
Please respond to ORACLE-L
To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]>
cc:
Subject: data warehousing desing - to denormalize or not to denormalize
- that is
the question
Hi.
We are designing a small database using a data
warehousing desing. We have created a 3rd normal form
and are now debating whether and how to denormalize
it. I see the pluses of denormalization - easier
queries creation and tuning. What are the
disadvantages that we should be aware of? Wasted space
is not an issue because the tables a pretty small.
What else should we consider as a potential issue?
thank you
__________________________________________________
Do You Yahoo!?
Yahoo! Shopping - Mother's Day is May 12th!
http://shopping.yahoo.com
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Gurelei
INET: [EMAIL PROTECTED]
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
San Diego, California -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
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:
INET: [EMAIL PROTECTED]
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
San Diego, California -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
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).
