SQL Clone
SQLServerCentral is supported by Redgate
Log in  ::  Register  ::  Not logged in

Interview with Chuck Kelley - Part I

By Robert Pearl,

Recently at a mutual client, I had the pleasure of meeting and working with a prominent individual skilled in the art of designing data warehouses.  Due to the nature and importance of this BI project, we pulled out all stops looking for the right person with the experience and knowledge that can do the job.  All bets were riding on this high-profile endeavor, as well as the reputation of IT as a whole on the ability to deliver the end-product to the business on time and in scope.  As we were forewarned by the architects of the system that we were facing an "impossible data warehouse" situation, we thought why not bring in the person who wrote the book? So, we did. Why settle for anyone less? 

Co-author of the book,  Impossible Data Warehouse Situations: Solutions from the Experts, Chuck Kelley - internationally known data warehouse expert - answers questions about himself, the profession, data-warehousing, Microsoft's venture into the world of Business Intelligence, and the tools behind it.   I've even asked him to comment on some of the articles relating to data warehousing, appearing here on SQLServerCentral.Com.

First, some background on Mr., Kelley's bona-fides. Chuck has 30 years of experience in designing and implementing operational/production systems and data warehouses. He has worked in some facet of the design and implementation phase of more than 50 data warehouses and data marts. He also teaches seminars, co-authored four books on data warehousing and has been published in many trade magazines on database technology, data warehousing and enterprise data strategies.  He is considered one of the early pioneers in the industry.

Currently, he participates on the 'Ask the Experts' panel for DMReview, the premier business intelligence, analytics and data warehousing publication site. I will even highlight and reprint some of those questions and answers here; that I think will be of interest to our audience. 

So, if you have questions on any of the aforementioned topics, feel free to post them at DMReview and chances are good that Chuck or one of his esteemed DW/BI colleagues will answer.  Or, if you have any project work in need of DW expertise, and would like to secure his services, he can be contacted directly at chuckkelley@usa.net.

As we collaborated closely on this project, I figured that this would be a great topic for an article of interest on SSC.com and share with you all things data warehouse from one of the industry's top professionals.  I'd be a fool to let an opportunity like this go by, so after a few database favors, he graciously agreed to the interview that I have brought you here today.

RP: What actually brought you into this field, and in particular data warehousing?  Give us a little background on how you started and evolved into this line of work 

CK:  In the late 80s, I was working at Digital Equipment Corporation (DEC) in the database group.  I noticed there was starting to be some buzz around data warehousing, but I was more in tune with operational systems.  In 1990, I saw a few books about Data Warehouse by this guy named W. H. Inmon.   

I called the editor of DM Review (at that time) and asked if he had Bill's number.  Turns out we lived in the same state and so I called to discuss his perspective.  Shortly afterward, we wrote a book on using DEC products in the data warehouse environment.  It was entitled "Rdb/VMS: Developing the Data Warehouse".  During that time, I also met another guy named Ralph Kimball, who was working on Red Brick Systems.  Between these two fine gentlemen, I learned a lot about business intelligence.  I am very honored to know and to have learned from them both. 

[If you've heard the name before, that's Bill Inmon, world-renowned expert, speaker and author on data warehousing, widely recognized as the "father of data warehousing" and creator of the Corporate Information Factory.

Ralph Kimball, is an author on the subject of data warehousing and business intelligence. He is known for long-term convictions that data warehouses must be designed to be understandable and fast - so, indeed Chuck is in good company!]

RP: When did you realize the value of the data warehouse to companies and advent of business intelligence in the enterprise? 

CK:  I realized in the early 1990 that the value to enterprises of any size was going to be fairly high.  At the time, I told DEC that I would like to move the consulting group I managed toward that arena, but they didn't see the benefit at that time.  There was still much to do with transaction systems.  And they were correct.  So I decided to depart from them and start my own consulting company dedicated to database (for the financial side!) and data warehouse (for the bleeding edge side).

RP: What advice would you give to others considering becoming a Data Warehouse architect?

CK:  You should know a lot about transaction system databases -- how they are built, the tradeoffs on the design, etc.  Then learn everything (by pushing to the back of your mind, but not forgetting, the things you learned about transaction systems!) you can about dimensional modeling.  Then learn how to read marketing brochures and articles (including mine!) critically, since every one of them will sound reasonable, but some of the ideas just won't work.

RP: BI is a broad term, what is the breakdown of functional jobs

CK:  I think there is a number of different type folks needed on BI project.  Project Manager, Data Modeler, DBA, User Interface/Report Developer, Business Analyst, ETL Developer are a few that come to mind.  You will also need production support type folks.

RP: Recently appearing on SSC.com, was an article entitled "From DBA to DWA" about the responsibilities of what he titled the "DWA" or data warehouse administrator. 

 - Do you agree with this categorization as a separation of duties from the dba.

 - How do you think the duties and tasks from the typical DBA vary from the DWA?

 - Does this accurately sum up the role and responsibilities of the DWA? 

CK:  Somewhat, I would agree, but I think that the DWA and DBA have very similar types of tasks and could probably be done by the same person/group.  This of course would be dependent on the size of the team, much like the question of how many DBA's do you need.

RP:  What do you think of a company charging the DBA to support the data warehouse?

CK:  Why not?  Of course, it depends on the definition of support and whether the DBAs are separated into Ops and Apps. 

[Fellow DBA's: One thing learned is to be sure that management understands the differences between database administration/operations support and development and design.  The DBA is often painted with a broad brush, and often we wear many hats, so make sure that expectations compliment the work you desire to do.]

To set up the next few questions, let me give the readers a quick overview in the varying paradigms in the data warehousing field.  Here, we often hear about discussions on where a person / organization's philosophy falls into Bill Inmon's camp or into Ralph Kimball's camp. Below is a brief summary on the difference between the two, and then we'll get Chuck Kelley's take on this.

Bill Inmon's paradigm: Data warehouse is one part of the overall business intelligence system. An enterprise has one data warehouse, and data marts source their information from the data warehouse. In the data warehouse, information is stored in 3rd normal form.   Based on this paradigm, he developed what's known as the Corporate Information Factory (CIF).  CIF is a logical architecture whose purpose is to deliver business intelligence and business management capabilities driven by data provided from business operations

Ralph Kimball's paradigm: Data warehouse is the conglomerate of all data marts within the enterprise. Information is always stored in the dimensional model.  In fact, the term dimensional modeling is also known as the Kimball methodology. 

RP: Is Bill Inmon's "Corporate Information Factory" DW model still valid in today's world?

CK:  Absolutely.

RP: What camp do you fall into Ralph Kimball vs. Bill Inmon?

CK:  Both.  I find very little difference between them other than the point of view. 

RP: Is one model superior over the other?

CK:  I see them as basically the same.  Bill talks about the data from a data management perspective and Ralph talks about it from the end user's access perspective.  Both speak of taking data from transactions system (and external data) storing them in a big storage area (data warehouse or staging).  Then from that, you build the data marts.  Yes, I know that there are some differences in how the DW and Staging areas are done, but I believe that is irrelevant.  I am sure if you talk to others, they will vehemently disagree with me, and that is their prerogative.  The great thing about the computer industry is there are multiple ways of doing things.  As long as it meets the needs of our user community AND has good performance AND does not cost too much AND fits our architected data environment, then all is good.

RP:  With respect to your current project, what were some of the challenges in specking out and coming up with the initial design?  How much iteration do you go through to come up with the final working DW model?

CK:  My current project had some issues with timelines, but we are slowly getting out of that problem.  So far we have gone through about 3 iterations, which is about where we should be at this time in the project.  I wish we had been through the first couple of iterations earlier, but that's OK.

RP: What are some of the most common questions you receive on data warehousing and business intelligence? 

CK:  I wrote a book on that exact topic and some friends of mine.  The title is "Impossible Data Warehouse Situations: Solutions from the Experts

Here is an excerpt on the book's stated purpose. "There is no reason that each organization, as it begins and continues to develop data warehoused projects, must wrestle with many of the very difficult situations that have confounded other organizations.  The same impossible situations continue to raise their ugly heads, often with surprisingly little relation to the industry, the size of the organization, or the organizational structure.  In this book we let you know that you are not alone and your problems are not unique.  We also offer hope to the perplexed who see no obvious solutions to their problems."

[This extremely detailed and well-organized book offers some very real-world practical considerations and solutions to embarking on the design and implementation of the data warehouse in one's organization.  You can grab a copy of this great tome on Amazon.com by clicking the above-entitled link.]

I'd like to end Part One of this interview with a public service message.  For all you hard-working DBA's out there putting in countless hours in overtime, and running 24x7 shops ,we owe Mr. Kelley a debt of thanks for his Dr. Phil moment, boldly answering this one question of damsel in distress vs. DBA - actually appearing DM Review Online. 

Should I be concerned about my boyfriend is spending 60 to 70 hours per week on a data warehouse project?

DMR: My boyfriend is a database administrator working on a data warehouse project. He claims the project requires that he works 60 to 70 hours/week. Since the project began, he seems distant and we hardly are intimate any more. I'm worried that he's seeing someone on the side. Should I be concerned?

CK:  First, let me say that I am not a psychologist, psychiatrist, social worker or counselor of any kind when it comes to relationships.  Just ask my wife! However, 60 to 70 hours per week a few times during major deployment times is not unreasonable. But, that would only be a week or two. I would be concerned that your boyfriend is going to kill himself due to overwork. My wife complains about me being distant during those same times. My suggestion is to ask him. (DM Review Online, December 24, 2007)

So, honey, I'll be home as soon as I possibly can! Keep my dinner warm for me.

In the next exciting installment of this two-part interview with Chuck Kelley, we'll drill down more into his thoughts on the Microsoft SQL Server Tools Suite, and answer some common questions about the art of Data Warehousing.

Written by: Robert Pearl, President
Pearl Knowledge Solutions, Inc.


Copyright ) 2008 - All Rights Reserved.

Note: Not to be reprinted or published without express permission of the author.


Total article views: 1586 | Views in the last 30 days: 4
Related Articles

Are you ready for Data Warehouses?

Data warehousing is being used more and more everyday and longtime data warehouse DBA Janet Wong bri...


Considerations for Data Warehousing

What type of things do you need to look at when setting up a data warehouse? Hardware is a big one a...


Using Data Warehouse for CRM

Usually a data warehouse is used for some sort of Business Intelligence system. Data warehousing exp...


Migrating Data Warehouse Systems to SQL Server 2005

Continuing with his fantastic series on data warehousing. Vincent Rainardi brings us the next instal...


Book Review: The Data Warehousing Toolkit 2nd Edition

Longtime author and SQL Server guru David Poole takes a look at a classic book about Data Warehousin...