SQLServerCentral Article

Interview with Chuck Kelley - Part I

,

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.

mailto:rsp05@pearlknows.com
http://www.pearlknows.com/

Copyright ) 2008 - All

Rights Reserved.

Note: Not to be

reprinted or published without express permission of the author.

 

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