Chuck Kelley is an internationally known expert in database and data warehousing technology. He has 30 years of experience in designing and implementing operational/production systems and data warehouses. Kelley 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 can be contacted at chuckkelley@usa.net.

Can data warehouses be designed to cover all possible queries on dimensions that we throw at it without providing a list of reports to an IT department?
March 7, 2008 First of all, some reports can be predicted. The reports users get today that will be satisfied by the data warehouse will...

Can anyone share some experience as to how to test a data warehouse?
March 7, 2008 Can anyone share some experience as to how to test a data warehouse? What kind of test cases needs to be written?

Which CDC method is the best to achieve staging database with changed data?
March 7, 2008 Which method is the best to achieve my goal (staging database with changed data) taking into consideration the issues of...

Apart from bloated dimension, what are the negatives of using all known attributes in your SCD?
March 7, 2008 Question: Apart from bloated dimension, what are the negatives of using all known attributes in your slowly changing...

When is it better to have normalized data to create data marts and when is it better to have dimensional data?
March 7, 2008 Hoping not be bombarded by emails, I still don’t get the difference between Kimball’s and Inmon’s approach.

What is the difference between a recommendation engine and predictive analytics?
March 7, 2008 Questions: I am interested to learn more about the difference between the “recommendation engine” and the predictive...

How do I convince my reluctant boss to begin work on a data warehouse?
December 24, 2007 It sounds, to me, that your boss is not ready for or does not comprehend what a DW can do for the organization.

When we deliver a data warehouse solution, the users tell us it doesn’t match what they need. What do we need to do?
December 24, 2007 How long did it take before you delivered the data? My guess is that it was longer than three months. Within three months, the...

Should I be concerned about my boyfriend is spending 60 to 70 hours per week on a data warehouse project?
December 24, 2007 First, let me say that I am not a psychologist, psychiatrist, social worker or counselor of any kind when it comes to...

What are your views on the advantages and/or disadvantages ETL tools and data modeling versus code?
November 28, 2007 Data modeling tools are inexpensive and writing code to provide the same function is pointless. You have too much work to do...

Is there a good book for BI project management that you would recommend?
November 28, 2007 Very soon there will be a very good book for Agile BI PM. I am hoping to publish it in the fall of 2008.

Should the metadata layer that sits between the data marts and the query/reporting tools be owned by the business or IT?
November 28, 2007 It depends on what is meant by “owned.” IT should provide the metadata repository along with the rules about who can...

What are dimension mapping and fact mapping?
November 1, 2007 It could be the process of mapping data from the source to its location in either a dimension or fact (assuming the target is...

When should we use vertical partitioning?
November 1, 2007 the question in a data warehouse is not whether to partition but how to partition. Both types of partitioning are beneficial...

What are the pros and cons of including non-foreign key attributes in fact tables that are not metrics?
November 1, 2007 Generally, I would not do it with a couple exceptions (and not always then): A single dimension has the same cardinality as...

When do you use a star schema and when to use a snowflake schema?
November 1, 2007 My personal opinion is to use the star by default, but if the product you are using for the business community prefers a...

What are the differences between ODS, EDW and a central repository and their specific uses?
October 31, 2007 Larissa Moss' Answer: An ODS is a database that is subject-oriented, integrated, volatile and current. It is usually used by...

How long a transition period is needed to safely change DW maintenance vendors?
October 31, 2007

How does the newest release of MySQL measure up to the task of managing a several GB database, especially in reporting?
September 4, 2007

Is there anything I can do in the design to account for the fact that I will always have to back out, reload, recast and rebuild aggregates on a regular basis?
August 1, 2007

What is the role and scope of ETL in the major archival of large amounts and variety of data?
August 1, 2007

Which would be a better choice of classes for career growth in data warehousing - ETL architecture or dimensional modeling?
August 1, 2007

We are building and enterprise data warehouse and are a bit confused about how to manage the information provider level or patient level.
August 1, 2007

Please give some advice for stress testing versus load testing; function testing versus performance testing; and load testing versus performance testing.
August 1, 2007

What is the best approach to get an integrated view of information of both my finance and sales/production systems?
August 1, 2007

Could you give some design tips on design requirement s for ad hoc and what-if analysis on a snapshot of the existing data in the DW?
August 1, 2007

How do you decide on the roles and responsibilities of operational or analytical reporting teams?
August 1, 2007

How much time is needed to clean the master data and get it on track?
July 2, 2007

Is there a best practice associated with the number of distinct databases that should be used in the overall warehouse?
July 2, 2007

What are the implications to staging area and ETL process of incorporating an ODS?
July 2, 2007

Do you have any specific suggestions about the use of a primary key in fact tables?
July 2, 2007

What is the difference between ER modeling and OLTP modeling? Is the result of ER modeling and OLTP model the same?
July 2, 2007

Are there any surveys that provide insight to what companies are spending to implement data warehousing solutions?
June 1, 2007

How would you keep three distribution center databases from growing into a very large database (VLDB), while giving the headquarters the ability to create an enterprise data warehouse (EDW) over the next two years if it is needed?
June 1, 2007

Are you aware of other financial services enterprises which have adopted this approach and if so would it be considered a best practice?
June 1, 2007

What impact does data privacy legislation have on using and building customer/employee data warehouses?
June 1, 2007

What is a junk dimension? Is that similar to a conformed dimension?
June 1, 2007

What is the relationship between performance measurement and strategy?
May 1, 2007

What's the latest in extending data warehousing services to mobile devices?
May 1, 2007

What are junk dimensions and degenerate dimensions?
May 1, 2007

Why hasn't the data warehouse and BI been more active in areas that go beyond just making money?
March 1, 2007

What are native connections? How are they different from ODBC connections? What are the advantages and disadvantages of native connections?
March 1, 2007

We are going to change the numbering format for our customers for database across the organization. What should we consider before beginning the project?
March 1, 2007

Is there an easy way for me to explain to an ER modeler why facts are in the center of a star schema and not dimensions?
March 1, 2007

Could you please supply a definition for "exploration data mart?"
March 1, 2007

What factors should be considered and what are the risks of bringing an outsourced data warehouse back in house?
February 1, 2007

How do you address concerns on security related to outsourcing?
February 1, 2007

How do other companies vet report requests from internal customers when rolling out the DW?
February 1, 2007

Would you suggest sources to implement a data strategy for enterprise applications?
February 1, 2007

What are the metrics a company should track?
February 1, 2007

Please suggest some hints/methodology to help us redesign the data model which will make all the reports obsolete.
February 1, 2007

Are there any industry standards or best practices regarding how to handle vendor solutions specifically pertaining to conformation to an organization's information architecture standards?
February 1, 2007

What is the best data modeling approach for a staging area?
February 1, 2007

What are the best methodologies for testing data integration?
February 1, 2007

Are dimension tables for a DW the same as those in a OLTP system?
January 2, 2007

Do you see the ODS and the DW blending into a single data store?
January 2, 2007

What, if any, is the difference between data warehouse compression and table/dataset compression?
January 2, 2007

Do you think a company is inefficient if they have more than 20 KPIs?
December 7, 2006

What are the pros and cons of having a data mart as a separate instance instead of with a data warehouse?
December 7, 2006

Can you run a marketing campaign without a data warehouse or data mart?
December 7, 2006

Can you take a small representative database from any organization and convert it into a data warehouse?
December 7, 2006

Please give a brief explanation of real time, online, time-sharing methods of data processing.
December 7, 2006

Please explain the difference between a point solution and an enterpise-wide solution.
December 7, 2006

What is the role of an enterprise data architect?
December 7, 2006

Would you recommend deleting inconsistent data in our sources?
November 9, 2006

What is associated query logic?
November 9, 2006

In a huge company which is dealing with large potential amounts of duplicated data, should we abandon the centralized data warehouse approach and opt for a more federated approach?
November 9, 2006

How confident can I be that my database management system tool and extract, transform and load tool will work together?
November 9, 2006

Can there be eight fact tables in a star schema?
October 3, 2006

What is the purpose and role of dimensional modeling during data warehouse development process?
October 2, 2006

What is a potential approach to provide clients performance reports customized to their needs?
July 10, 2006

What are some best practices for validating data in staging tables after the ETL process has moved the data from the source to the warehouse staging tables?
July 10, 2006

Would you advocate a business rules enforced enterprise repository (ER) structure first, then a data mart for your source reports and then having the ER serve as a drill-down repository?
July 10, 2006

In building fact tables, what is the best practice for refreshing the data?
July 10, 2006

Ask the Experts
May 5, 2006

Ask the Experts
April 21, 2006 Should the operational data store be designed using 3NF approach or a dimensional approach? What is the best design approach...

Would you suggest recovery strategies in data warehousing while loading high volumes of data?
April 10, 2006

Should the operational data store be designed using 3NF approach or a dimensional approach?
April 10, 2006

How do star schemas compare to snowflake schemas?
April 10, 2006

Are open sources capable of handling huge volume of data?
April 10, 2006

What is the best solution for a data capture issue, where the source tables don't have proper timestamp capture for the updates?
April 10, 2006

Ask the Experts
April 7, 2006 This is a sample of the questions asked of and answered by our illustrious panel of experts.

What are some best practices for customer data matching, cleansing and integration when your customers are public and private institutions in a variety of industries?
March 5, 2006

After almost completing the first iteration of our data warehouse base facts and dimensions, is it reasonable to convert to an ETL tool instead of using templates to assure consistency and accuracy?
March 5, 2006

What is an effective way of recouping the running costs of the data warehouse from the business users, without impacting usage of the DW?
March 5, 2006

How would you generate a report that shows non-events in a fact table?
February 7, 2006

How does data warehousing apply to machine monitoring information?
January 3, 2006

Is there any database management system which supports temporal databases?
January 3, 2006

What is the most appropriate schema architecture for a data warehouse with downstream dependent data marts?
December 12, 2005

What are the advantages of ETL tools over Pl/SQL loaders?
December 12, 2005

What activities and skill sets distinguish and differentiate a data warehouse DBA from a traditional Oracle production DBA?
October 7, 2005

how we can implement the concept of a centralized data warehouse in Ralph Kimball's approach by building a set of data marts for enterprise data warehouse?
October 7, 2005

Can you recommend any books or papers or an approach to obtain a common customer view?
October 7, 2005

Can anyone recommend DW training?
September 7, 2005

What is the relationship between the data warehouse and its portal?
September 7, 2005

Is real-time integration or staging generally a better approach for enterprise-class software?
September 7, 2005

Could you please let me know the advantages of ETL tools versus traditional programming?
September 7, 2005

Can anyone provide a summary of how ISO 11179 and OMG CWM are related and where each pertains to a meta data repository project?
September 7, 2005

We're having trouble deciding just who does what and when they do it in the development life cycle.
September 7, 2005

Is there is any standard methodology for the use of ETL tools or does it depend on the tool itself? We are at the process of buying a tool.
August 4, 2005

Is any security policy relevant to business intelligence or data warehousing?
August 4, 2005

Do you recommend keeping the same surrogate keys for a row in the ODS and in the data warehouse or can you assign different surrogate keys by data store?
August 4, 2005

Is it wrong to build a billing application off the ODS?
August 4, 2005

Please identify dimensions, facts and a schema for the higher education domain.
August 4, 2005

From a quality assurance (QA) perspective, if the ETL process, dimensions and fact tables are tested properly, is it mandatory to verify the cube?
August 4, 2005

Do you recommend keeping the same surrogate keys for a row in the ODS and in the data warehouse or can you assign different surrogate keys by data store?
August 4, 2005

Are snowflaked tables the sign of bad architecture?
August 4, 2005

It is difficult to design reports on an OLTP-oriented database with OLAP tools and some additional algorithmic language was needed to manage the records values in the SQL end result. Could you validate that view?
June 8, 2005

Which set of skills would be more pertinent for a data quality and support team leader, a technical skill or a business related skill?
June 8, 2005

I am engaged in building a Web server log analysis tool for which I need a database to store the sorted data from the log file. Should I use a data warehouse or a simple relational database?
June 8, 2005

What is your opinion on the viability of a "general purpose" BISP and why are there so few?
June 8, 2005

If I have a CBAT tool like smartFOCUS, why would I need an OLAP tool too?
June 8, 2005

What is a junk dimension and could you provide an example?
May 2, 2005

Would you advise creating a junk dimension for a single flag? Also, when is it a good idea to create a junk dimension table?
May 2, 2005

What are your thoughts on operational reporting coming from a DW environment supporting legal or contractual obligations?
May 2, 2005

Do you have any suggestion for a design solution for our claims warehouse with potentially 2-6 billion claims?
May 2, 2005

How do you create a dimensional model for an educational institution using the nine-step methodology for data warehouse database design? Can I have a sample design?
April 3, 2005 How do you create a dimensional model for an educational institution using the nine-step methodology for data warehouse...

Could anyone please highlight the pros and cons of using products where you have to create such data clouds, compared to constructing OLAP cubes?
April 3, 2005 I am currently engaged in a BI (BSC) project. I have reviewed a couple of BI (BSC) tools and have come across several products...

Is there a software tool that monitors and controls the DW/BI processes?
April 3, 2005 We have a client looking for a DW tool that monitors/controls the DW and BI processes (e.g., what processes are scheduled to...

What is the difference between analytics and data mining?
February 4, 2005 What is the difference between analytics and data mining? A search on "Ask the Experts" helped me to get the difference...

What are the downsides, if any, to "data warehouse appliances?"
February 4, 2005 My company is looking at what are being called "data warehouse appliances." They seem to be cheaper than conventional data...

We are building a data warehouse with many source systems that provide data feeds.
February 4, 2005 We are building a data warehouse with many source systems that provide data feeds. In order to reduce the volume of data, we...

Since hardware is relatively inexpensive, does my company have to worry about performance?
February 4, 2005 Since hardware is relatively inexpensive, does my company have to worry about performance? Can't we just throw more hardware...

I am in a migration project which involves data extraction from Oracle tables to flat files for different systems.
January 3, 2005 I am in a migration project which involves data extraction from Oracle tables to flat files for different systems. I need to...

How do we model a fact table in which the measures are constantly changing?
January 3, 2005 How do we model a fact table in which the measures are constantly changing? Is updating a fact table a good thing to do? Or is...

Please define data reconciliation and database reconciliation.
January 3, 2005 Please define data reconciliation and database reconciliation. I also need a definition of data synchronization.

Are there any standard practices to follow in regards to intermingling application data with warehouse data?
January 3, 2005 Are there any standard practices to follow in regards to intermingling application data with warehouse data? We now have an...

Could you clarify the difference between the terms: data hub and staging area and identify where they fit in a corporate architecture?
January 3, 2005 Could you clarify the difference between the terms: data hub and staging area and identify where they fit in a corporate...

We are extracting data from a legacy system that has summary data in it that we will need in the DW, should we re-derive these counts as functions of ETL to ensure accuracy?
November 1, 2004 We are extracting data from a legacy system that has summary data in it that we will need in the DW, assuming that the legacy...

How do we map all the OLTP schema to OLAP to answer queries about historical information in the data warehouse?
November 1, 2004 We have database which stores our enterprise data and we need to keep track of the history of the information relevant to...

How does business intelligence (BI) relate to geographic information systems (GIS)?
November 1, 2004 How does business intelligence (BI) relate to geographic information systems (GIS)?

Are there standards or best practices for report presentation?
November 1, 2004 I am working with operational reports. Do you know if there is something like standards or best practices for report...

When designing the dimension for a call center do I keep the information in a denormalized form or break it into logical mini dimensions?
November 1, 2004 We are building a data mart for a hotel chain's call center. We have a huge customer information table in the source...

Would you interview top executives separately or as a group for the collection of business requirements via interviews?
October 14, 2004 Would you interview top executives (CEO, COO, CFO), vice presidents and directors of functional areas separately or as a group...

How do 3NF and 1NF compare and contrast in VLDB? What advantage does the 3NF design have for a VLDB?
October 14, 2004 How do 3NF and 1NF compare and contrast in VLDB? What advantage does the 3NF design have for a VLDB?

What aspects do I need to consider for an ETL tool for a strategic data warehousing development project in banking domain?
October 14, 2004 What aspects do I need to consider for an ETL tool for a strategic data warehousing development project in banking domain? The...

Where can I find reviews on an ETL tool that will support Unicode?
October 14, 2004 We are looking for an ETL tool to replace our current tool which was developed internally. I'm under the gun to find an ETL...

Have you heard of GIS systems integrated directly with the data warehouse being done before and how it was achieved?
October 14, 2004 A number of our clients have expressed interest in being able to integrate their GIS systems directly with the data warehouse...

We about to establish a new IT section, using Oracle9i with a UNIX operating system.
September 8, 2004 We about to establish a new IT section, using Oracle9i with a UNIX operating system. Do you think it is better to purchase two...

We have a data consolidation system which takes transactions from multiple systems and consolidate and enriches it with contextual information and publishes the same to the downstream consumer systems.
September 8, 2004 We have a data consolidation system which takes transactions from multiple systems and consolidate and enriches it with...

I am a computer science student, and I want to implement a data warehouse using free software on Linux.
September 8, 2004 I am a computer science student, and I want to implement a data warehouse using free software on Linux. The data I am going to...

I am working in the HR data warehousing application in Ford Motor Company.
August 13, 2004 We are planning to follow a CIF architecture in which we bring all the data in the warehouse in normalized form and then...

I have several years in QA and testing of software and am now working on my first data warehouse assignment.
August 13, 2004 I have several years in QA and testing of software and am now working on my first data warehouse assignment. I am having...

I recently joined the company as a DW data modeler in the production support group.
August 13, 2004 I recently joined the company as a DW data modeler in the production support group. The DW is large and was partially...

What are the risks involved when doing data integration?
August 13, 2004 What are the risks involved when doing data integration?

I'm being asked to add a "deprecator" indicator to my code tables to indicate when a valid value is no longer used.
July 8, 2004 I'm being asked to add a "deprecator" indicator to my code tables to indicate when a valid value is no longer used. This...

The new trend has been demanding real-time data from the data warehouse.
July 8, 2004 The new trend has been demanding real-time data from the data warehouse: 1) to generate operational report at high...

This has to do with a data design issue.
July 8, 2004 This has to do with a data design issue. The setting is a shipping company, but I'll ignore the usual from/to, customer,...

We are currently evaluating several BI solution options and realized that there are solutions that manage by data kept in data warehouses and those that manage by data kept in analysis cubes.
July 8, 2004 We are currently evaluating several BI solution options and realized that there are solutions that manage by data kept in data...

It has been suggested that we can skip user acceptance testing of the Dimension tables in order to speed up implementation.
July 8, 2004 It has been suggested that we can skip user acceptance testing of the Dimension tables in order to speed up implementation....

For an aggregated fact table which requires its data to be dimensioned by gender and age (in years), is there any benefit in creating these as dimensions at all even if it may help in cross fact analysis or not to bother as the gender and age values would be the same as the dimensional key values (i.e., age_key 16 for 16-year-olds)?
July 8, 2004 For an aggregated fact table which requires its data to be dimensioned by gender and age (in years), is there any benefit in...

What is the difference between federated data warehousing and distributed data warehousing?
May 7, 2004 What is the difference between federated data warehousing and distributed data warehousing?

What factors should an organization consider when determining how often to "refresh" (update) its data warehouse?
May 7, 2004 What factors should an organization consider when determining how often to "refresh" (update) its data warehouse? Is it...

I've recently hired on to administer and manage a previously designed data warehouse.
May 7, 2004 I've recently hired on to administer and manage a previously designed data warehouse. To my surprise, the active physical...

In designing a star schema for grocery, we have promotion dimension.
May 7, 2004 In designing a star schema for grocery, we have promotion dimension. Should we have the promotion key as part of the primary...

Can you tell me how to distinguish reporting that is done from an OLTP system vs. reporting that is done from an ODS?
May 7, 2004 Can you tell me how to distinguish reporting that is done from an OLTP system vs. reporting that is done from an ODS? We...

I will be extracting data from SAPR/3 and flat files and loading into my SAP-BW system.
April 27, 2004 I will be extracting data from SAPR/3 and flat files and loading into my SAP-BW system. How do I go about evaluating ETL...

Where can I find a case study on the data warehousing life cycle?
April 27, 2004 Where can I find a case study on the data warehousing life cycle? I’ll be building a cube in a star schema within the...

I have a question on best practices to be used in designing a data warehouse.
April 27, 2004 I have a question on best practices to be used in designing a data warehouse. Assuming the data warehouse requires both an...

I have come across two approaches/practices in building data warehouses.
April 27, 2004 I have come across two approaches/practices in building data warehouses. One is constructing a data warehouse at the...

I am preparing a document for effort estimation for data warehousing projects.
April 27, 2004 I am preparing a document for effort estimation for data warehousing projects. Currently we are using WBS (work breakdown...

Can you give a three-dimensional size example of what a data warehouse would be to support a four year university?
March 13, 2003 Can you give a three-dimensional size example of what a data warehouse would be to support a four year university?

Is there a "known" list of data quality principles?
March 13, 2003 Is there a "known" list of data quality principles?

We are planning to implement a data warehouse. What are the advantages/ disadvantages of using Oracle database over Teradata?
March 13, 2003 We are planning to implement a data warehouse. What are the advantages/ disadvantages of using Oracle database over Teradata?

We are involved with a DW strategy and planning a CRM strategy.
February 3, 2003 We are involved with a DW strategy and planning a CRM strategy. The company needs information now, and we can't wait for...

We are building a DW for our distribution company.
February 3, 2003 We are building a DW for our distribution company. We are defining the metrics and key performance indicators (KPIs) to...

My customer information is spread over multiple systems on different platforms.
February 3, 2003 My customer information is spread over multiple systems on different platforms (Windows, UNIX, mainframe). The requirement...

I am developing a system which deals with a large amount of data - what are the storage configuration and technology more suitable for that system?
February 3, 2003 I am developing a system which deals with a large amount of data: Typical file size 50 MB – 350 GB Number of files...

I have a small problem relating to the relationships that exist between a dimension table and a fact table.
February 3, 2003 I have a small problem relating to the relationships that exist between a dimension table and a fact table. There are two...

I am currently a student at college. We have an assignment to do on CRM.
January 13, 2003 I am currently a student at college. We have an assignment to do on CRM. We have to develop a CRM and convince the board...

Can we and should we adopt different data modeling schemas during the extraction, transformation and staging method?
December 2, 2002 Can we and should we adopt different data modeling schemas during the extraction, transformation and staging method? What...

When it comes to the design technology of enterprise data warehouse (EDW), some people are insisting we use Inmon's approach of top-down methodology.
December 2, 2002 When it comes to the design technology of enterprise data warehouse (EDW), some people are insisting we use Inmon's...

What is the industry standard benchmark for data warehouse customer usage?
December 2, 2002 What is the industry standard benchmark for data warehouse customer usage? I am particularly interested in comparing the...

If there are 10 data marts which use different schemas (some use star and the others use snowflake), will inconsistencies arise designing a data warehouse using a bottom up approach?
December 2, 2002 If there are 10 data marts which use different schemas (some use star and the others use snowflake), will inconsistencies...

Do you suggest surrogate keys in data marts and/or EDW solutions?
December 2, 2002 Do you suggest surrogate keys in data marts and/or EDW solutions?

How can I use data warehousing or data mining in order to use a variety of information on several products covered in the survey?
December 2, 2002 I am a data analyst in a media research company where we conduct a very large survey of sample size approx. 2,25,000 a...

I have two questions...
December 2, 2002 Do you know what would be a good book that talks about warehousing server/hardware to support technical and user...

Assuming that the applications and databases are on separate machines, what is the current thinking on where the data warehouse database should reside?
December 2, 2002 Assuming that the applications and databases are on separate machines, what is the current thinking on where the data...

I recently wrote a dissertation where I developed a generic data mining life cycle.
November 5, 2002 I recently wrote a dissertation where I developed a generic data mining life cycle. I am also very interested in urban...

What is the role of genetic algorithms in data mining?
September 11, 2002 What is the role of genetic algorithms in data mining? What are the other perspectives in which we can see the use of...

We are having a little debate here regarding the use of codes along with their related descriptions in our the relational dimensions (not the OLAP dimensions).
September 4, 2002

Industry standards state that the typical star schema will have about six dimension tables and the associated fact tables depending on grain, etc.
September 4, 2002 Industry standards state that the typical star schema will have about six dimension tables and the associated fact tables...

My company needs a central location for all customer-related data.
August 26, 2002 My company needs a central location for all customer-related data. There are no specific facts associated with customer...

Are there sample documents on what to test in a data warehouse environment?
August 26, 2002 Are there sample documents on what to test in a data warehouse environment? What are some test strategies for data...

Report generation (BI) which searches and retrieves data from very large tables has resulted in slow database response-time and affecting the whole db performance.
August 26, 2002 Report generation (BI) which searches and retrieves data from very large tables has resulted in slow database response-...

My company wishes to study changes to its customer file.
July 26, 2002 My company wishes to study changes to its customer file. A customer may be ranked a "10" one day and only a "9" the next....

Please explain the architecture of a data warehouse or direct me to books with figures so that I can visualize it.
June 25, 2002 Please explain the architecture of a data warehouse or direct me to books with figures so that I can visualize it.

What does migration to the architected environment mean?
June 25, 2002 What does migration to the architected environment mean?

What does granularity mean in the context of a data warehouse and what are the various levels of granularity?
June 25, 2002 What does granularity mean in the context of a data warehouse and what are the various levels of granularity?

We have a successful data warehouse (which is to say that business users are asking for more at an accelerating rate) and I am having a real
June 25, 2002 We have a successful data warehouseand I am having a real problem getting the business users and other IT groups to...

I am in the process of designing the data model for the data warehouse. Is star schema or snowflake better?
June 25, 2002 I am in the process of designing the data model for the data warehouse. Is star schema or snowflake better?

We have implemented a data warehouse and we use OLAP (Essbase) and MS Access to query the data in the warehouse.
June 25, 2002 We have implemented a data warehouse and we use OLAP (Essbase) and MS Access to query the data in the warehouse. We need a...

This is my first query to you. I know bits and pieces about BI and the data warehouse.
June 25, 2002 This is my first query to you. I know bits and pieces about BI and the data warehouse. I have experience in OLTP systems....

Is DTS suitable as a sole ETL tool?
May 3, 2002 Is DTS (MS SQL) really suitable as the sole ETL tool when it comes to the daily operation (and support) of a data...

Which tools and database should we select to implement a data warehoue?
May 3, 2002 We want to implement a DW. Which tools and database should we select? Please compare Teradata with ORACLE and its tools for...

What is the difference between summary and aggregate data?
May 3, 2002 This is a simple data mart question. What is summary data? Most books and white papers state that the star schema contains...

What are the recent trends in terabyte-size data warehouse backups?
May 3, 2002 What are the recent trends in data warehouse backups where the size of the warehouse is in terabytes? Are full online...

Could you please give me an idea of the typical range on a per record basis for a deduplication(data cleansing) project?
May 3, 2002 Could you please give me an idea of the typical range on a per record basis for a deduplication(data cleansing) project?

What products perform well on an OS/400 platform?
May 3, 2002 I am working on an OS/400 Platform, setting up a data warehouse structure for my company. A fact table of 5,000,000 records...

Is there a Web site where I can find all the major BI/Analytics vendors that have optimized their products for MS SQL Server?
April 17, 2002 Is there a Web site where I can find all the major BI/Analytics vendors that have optimized their products for MS SQL...

Looking into building a cube(s) to house purchasing data such as commodities, vendors, unit costs, etc.
April 17, 2002 We are looking into building a cube(s) to house purchasing data such as commodities, vendors, unit costs, etc. Need to know...

How could developers improve the use of DSS and EIS with DW technology?
April 17, 2002 How could the developers improve the use of DSS and EIS based on DW technology?

Can you provide me with the top data warehouse solution providers?
April 17, 2002 Can you provide me with the top data warehouse solution providers?

Regarding dimensional modeling vs. OLAP modeling.
March 13, 2002 Regarding dimensional modeling vs. OLAP modeling. Should these tasks have separate titles and roles or are they one and the...

Can you identify some companies and products (other than Vality Corp. and their Integrity product) that can perform probabilistic matching on company names?
March 13, 2002 Can you identify some companies and products (other than Vality Corp. and their Integrity product) that can perform...

I need to extract the database structure details to a specific location of an already created Business Objects universe.
March 13, 2002 I need to extract the database structure details to a specific location of an already created Business Objects universe. How...

I am looking for a reporting tool with a simple report development interface.
February 7, 2002 I am looking for a reporting tool with a simple report development interface. The usual suspects (BO, Brio, Cognos) are too...

One of our business requirements is to enable cause-effect analysis on two or more facts – such as sales and advertising expense.
February 7, 2002 One of our business requirements is to enable cause-effect analysis on two or more facts – such as sales and advertising...

I'm currently in the process of gathering the business requirements for an enterprise data warehouse.
February 7, 2002 I'm currently in the process of gathering the business requirements for an enterprise data warehouse. One of them is the...

During the first meeting with one of my prospects (a large Italian tire and cable manufacturer) the IT person responsible of the DW in the company told me:
February 7, 2002 Building a fact from the product creates a big hassle when I need a product dimension to analyze other key performance...

We currently have a normalized group-wide data warehouse based on a UNIX/Oracle platform.
February 7, 2002 We have looked at Oracle Warehouse Builder and although for simple ETL it seems it will handle the job, for more complex...

We are running out of extension field in fact tables (of a star schema dimensional model) and considering the creation of extension fact tables for additional extension fields.
February 7, 2002 We are running out of extension field in fact tables (of a star schema dimensional model) and considering the creation of...

We are implementing a balanced scorecard (BSC) application and are going to use our existing data warehouse as the source system.
February 7, 2002 We are implementing a balanced scorecard (BSC) application and are going to use our existing data warehouse as the source...

How would you characterize the difference between Bill Inmon's philosophy on data warehousing and Richard Kimball's?
January 25, 2002 How would you characterize the difference between Bill Inmon's philosophy on data warehousing and Richard Kimball's? As a...

I am looking into data warehousing conferences for training purposes.
January 25, 2002 I am looking into data warehousing conferences for training purposes. I have found two, one sponsored by The Data...

This is with respect to the DW Design.
January 25, 2002 This is with respect to the DW Design. Currently all our reports retrieve the measures using the SELECT DISTINCT clause even...

I'm designing a star schema for a client for reporting on the use of several systems.
January 25, 2002 I'm designing a star schema for a client for reporting on the use of several systems. Every single usage of a system is...

We are developing a VLDB that will probably use aggregate tables as well as database partitioning.
January 25, 2002 We are developing a VLDB that will probably use aggregate tables as well as database partitioning. Which databases are...

I have heard about reports which are created by joining more than one multidimensional cube.
December 14, 2001 I have heard about reports which are created by joining more than one multidimensional cube. Isn't it difficult to join more...

Do you know the limitation of Oracle Materialized View? Could MV create and manage summary data from remote database?
December 13, 2001 Do you know the limitation of Oracle Materialized View? Could MV create and manage summary data from remote database?

Why has the concept of data warehousing become popular?
December 13, 2001 Why has the concept of data warehousing become popular?

I'm evaluating DataStage from Ascential and PowerCenter from Informatica they seem to have pretty similar functionality, can anyone tell me what the main differences between them are?
November 20, 2001 I'm evaluating DataStage from Ascential and PowerCenter from Informatica they seem to have pretty similar functionality,...

Could you give me some help in finding DWs in the steel industry?
November 20, 2001 Could you give me some help in finding DWs in the steel industry? Or an example of using DW in quality control?

I've just finished my MBA (systems) and I am looking forward to a career in data warehousing.
November 20, 2001 I've just finished my MBA (systems) and I am looking forward to a career in data warehousing. Kindly advise me on the specific...

We are investigating implementing a warehouse in Oracle using Oracle 8i, which will merge enterprise-wide data.
November 20, 2001 We are investigating implementing a warehouse in Oracle using Oracle 8i, which will merge enterprise-wide data. Could you...

According to dimensional modeling theory, a fact table's primary key should be composed of multiple foreign keys...
November 20, 2001 According to dimensional modeling theory, a fact table's primary key should be composed of multiple foreign keys, one...

Apart from stored procedures what is the best language for writing data cleansing and transformation code for any DW?
November 19, 2001 Apart from stored procedures what is the best language for writing data cleansing and transformation code for any DW?

Our consultant is proposing the use of both the star and snowflake schemas in our datamart architecture.
November 19, 2001 Our consultant is proposing the use of both star and snowflake schemas in our datamart. Is this a typical practice in the...

Please provide some information on the advantages and disadvantages of using Teradata over DB2 for a larger database.
July 23, 2001 Please provide some information on the advantages and disadvantages of using Teradata over DB2 for a larger database....

We are building a data warehouse on AS/400.
July 23, 2001 We are building a data warehouse on AS/400. We plan to build this on a separate logical partition (LPAR2) outside of the...

Does your company has any products that can calculate profitability in three dimensions: customer, contract or transaction (banking universe)?
July 23, 2001 Does your company has any products that can calculate profitability in three dimensions: customer, contract or...

I am designing a star schema with a product dimension.
June 4, 2001 I am designing a star schema with a product dimension. One attribute of a product is not unique to the product itself.

Does it make a difference in query performance if I write tableA.colx = tableB.colY or the other way round?
June 4, 2001 Does it make a difference in query performance if I write tableA.colx = tableB.colY or the other way round? Is this...

My firm has been asked to perform the feasibility study for a meta data.
June 4, 2001 What questions should I ask the organization's technical stakeholders? Also, which toolsets would facilitate the...

How does one take care of normalization while designing the schema?
June 4, 2001 How does one take care of normalization while designing the schema?

How can someone who has no experience in these tools choose one?
June 4, 2001 There are many OLAP tools like Hyperion Essbase, Seagate Holos, Business Objects, etc. How can someone who has no experience...

What is the future of enterprise information portals? Are intranet and e-business portals EIPs?
June 4, 2001 What is the future of enterprise information portals? Are intranet and e-business portals EIPs?

Why might data be duplicated in a distributed document database?
June 4, 2001 What is a distributed database? Why might data be duplicated in a distributed document database? What problems does...

Could you give me a brief history of datawarehousing and comment on its expected future, please?
June 4, 2001 Could you give me a brief history of datawarehousing and comment on its expected future, please?

What are the performance tuning considerations to be kept in mind while designing this?
June 4, 2001 I am designing a data mart for a client that must be implemented on Oracle 8i and Sun Solaris. What are the performance...

I have several questions regarding testing.
April 30, 2001 I have several questions regarding testing. What key issues should I consider when testing a specific warehouse solution?...

How many databases have been sold in the past year?
April 30, 2001 How many databases have been sold in the past year?

We have a DSS system and use it to calculate profit at a slightly aggregated level.
April 30, 2001 Is there a technique we could use in designing tables to deal with changing history for profit as well as store/region?

What is the best source of information for populating a geographic hierarchy dimension?
April 30, 2001 What is the best source of information for populating a geographic hierarchy dimension? There seem to be many services...

What is the general criteria or guidelines for selecting the extraction, transformation and load (ETL) tools best suited for your data warehouse?
April 30, 2001 What is the general criteria or guidelines for selecting the extraction, transformation and load (ETL) tools best suited for...

How can I find the best available business intelligence tool?
April 30, 2001 How can I find the best available business intelligence tool?

In what types of business are data mining and data warehousing needed and how are they implemented?
April 2, 2001 In what types of business are data mining and data warehousing needed and how are they implemented?

We are currently designing the processes needed for obtaining customer data for customer relationship management (CRM).
April 2, 2001 We are currently designing the processes needed for obtaining customer data for customer relationship management (CRM)....

What is Teradata? I am seeing many requirements for this. How do I get the software and downloads of material for Teradata?
April 2, 2001 What is Teradata? I am seeing many requirements for this. How do I get the software and downloads of material for Teradata?

I have been asked to compare two data warehouse products from Brio and Cognos.
April 2, 2001 I have been asked to compare two data warehouse products from Brio and Cognos. What are some of the things that I should...

What are the growth prospects in the field of data warehousing if one takes it up as a career?
January 12, 2001 What are the growth prospects in the field of data warehousing if one takes it up as a career?

We are currently seeking to establish a reporting framework for our organization.
January 12, 2001 What is the best approach to demonstrate the benefits of a consolidated reporting framework?

We are planning to move legacy data from IMS/MVS, DB2 etc.
January 12, 2001 We are planning to move legacy data from IMS/MVS, DB2 etc. Can you suggest good extraction and transformation tools for...

I have to build a prototype pilot project for a media client.
January 12, 2001 I have to build a prototype pilot project for a media client. Should I carry out the same phases of activity, which should be...

What can’t my operational reports (from my ERP system) offer me what a business intelligence system can?
January 12, 2001 What can’t my operational reports (from my ERP system) offer me what a business intelligence system can?

We are in the process of determining the best approach to update our data structure supporting our OLAP solutions from it's current structure of flat files to a data mart or data warehouse structure.
January 12, 2001 Do you have any recommendations as to the effectiveness of building your own ETL tool or buying an existing tool?

I work in a big data warehouse and we are using ETI*EXTRACT as ETL tool.
January 12, 2001 I work in a big data warehouse and we are using ETI*EXTRACT as ETL tool. I know EXTRACT very well, but I'd like to get an...

Is it necessary to create a data warehouse separate from the operational data store (ODS)?
December 13, 2000 Is it necessary to create a data warehouse separate from the operational data store (ODS)?

What do you think of an object-relational database warehouse platform? Does it make it easier to build a data warehouse? What are the advantages and disadvantages?
December 4, 2000 Does an object-relational database warehouse platform make it easier to build a data warehouse?

Because of competition, we’re moving more into the retail industry, and need to alter our data warehouse to suit.
December 4, 2000 Our new customer-focused operational systems will involve CRM and outsource systems. As a result of this infrastructure, we’re...

What are the disadvantages of having a data warehouse in place?
December 4, 2000 Are there any disadvantages to having a data warehouse in place?

Should data be changed in the data warehouse and/or data mart making it different from the source system it came from?
December 4, 2000 Should data be changed in the data warehouse and/or data mart making it different from the source system it came from? What...

How is the acceptance of Microsoft OLAP services as a replacement to Essbase or express?
October 30, 2000 How is the acceptance of Microsoft OLAP services as a replacement to Essbase or Express?

I am trying to build a MDD from a relational Oracle Database using Oracle Express Server. Should I have the RDBMS and MDD on the same machine or on a separate machine? What are the pros and cons?
October 30, 2000 I am trying to build a MDD from a relational Oracle Database using Oracle Express Server. Should I have the RDBMS and MDD on...

What tools would you recommend for extracting and the manipulation of large data sets?
October 30, 2000 What tools would you recommend for extracting and the manipulation of large data sets?

Can you recommend any commercially available standalone packages for time-sequence analysis?
October 30, 2000 Can you recommend any commercially available standalone packages for time-sequence analysis?

I was wondering if there was a reason for or against using precision in numeric surrogate keys
October 30, 2000 Are there reasons for or against using precision in numeric surrogate keys in either a staging or presentation (star)...

I am looking for typical data warehouse project phases and the percentage of duration for each phase. Are there any resources or Web sites that collect this type of data?
October 30, 2000 I am looking for typical data warehouse project phases and the percentage of duration for each phase. Are there any resources...

What (if any) pros or cons come with creating summary tables in your data marts? An example would be to role up product revenue on a daily, weekly or monthly level.
October 30, 2000 What (if any) pros or cons come with creating summary tables in your data marts?

As CRM grows in importance in the e-economy, what do you perceive to be the market perception of data warehousing/data mining?
October 30, 2000 As CRM grows in importance in the e-economy, what do you perceive to be the market perception of data warehousing/data mining?

I've recently inherited a data warehouse that uses disk mirroring, and we're faced with the need to add about a terabyte (mirrored) to make it through the end of 2000.
September 1, 2000 Is it a common practice for data warehouses to use disk mirroring?

We are currently evaluating meta data repository tools and the vendors sell themselves through their flexibility and extensibility.
September 1, 2000 Is there a vendor that can provide a "canned" meta data model so we don't have to define our own from scratch?

Is there an OLAP tool available that has direct connectivity to an Oracle database, or is using a text file the norm when dealing with Oracle?
September 1, 2000 Is there an OLAP tool available that has direct connectivity to an Oracle database?

Is it possible to make data model before ERP system implementation and a data warehouse?
September 1, 2000 Is it possible to make a data model before an ERP system implementation and a data warehouse?

What are the changes required in order to convert a star schema warehouse to a snowflake schema warehouse?
September 1, 2000 What are the changes required in order to convert a star schema warehouse to a snowflake schema warehouse?

An operational data store (ODS) is different from data warehouse, but it is one part of data warehouse. Do you agree?
September 1, 2000 An operational data store (ODS) is different from data warehouse, but is it part of a data warehouse?

What are the best methods to understand requirements for a data warehouse? Are there specific format requirements for gathering, analysis and planning?
September 1, 2000 What are the best methods to understand "requirements" for a data warehouse?

I am very keen to move into the database sector. What are the typical day-to-day tasks of a DBA?
September 1, 2000 I am very keen to move into the database sector. What are the typical day-to-day tasks of a DBA?

I'm looking for a middleware product that sits between an SQL-issuing application and multiple physical database instances that are segmented by table and primary key range.
August 1, 2000 Do you have any thoughts about a tool that can provide a connection manager and SQL router function where all database...

I am working on a data warehouse design and the client needs real-time updates in the DW/DM from a one-source system.
August 1, 2000 Any ideas on how to accomplish a real-time update in the DSS environment?

When should we use an ETL tool and when should we develop one by ourselves?
August 1, 2000 When should we use an ETL tool, and when should we develop one by ourselves?

We are a service organization that handles campaign-based response (calls, e-mail and e- forms).
July 1, 2000 Do you know if there are solutions for service organizations that handle a lot of responses in a multi-channeling,...

What is the best way to deal with currencies in a data warehouse for a worldwide organization that wishes to allow people to view their data in local, reporting currency?
July 1, 2000 What is the best way to deal with currencies in a data warehouse for a worldwide organization that wishes to allow people to...

What are the best practices when it comes to deciding between a mainframe and NT environment for a data warehouse.
July 1, 2000 What are the best practices when it comes to deciding between a mainframe and NT environment for a data warehouse?

What do you think are the most important criteria when selecting a data storage vendor?
July 1, 2000 What do you think are the most important criteria when selecting a data storage vendor?

I'm interested in knowing the elements/dimensions that would be required to build a customer data mart and marketing data mart for an e- commerce company.
July 1, 2000 What are the elements/dimensions that would be required to build a customer data mart and a marketing data mart for an...

Is there a rule concerning aggregates tables mirroring the fact tables?
June 1, 2000 Is there a rule concerning aggregates tables mirroring the fact tables?

I'm in charge of defining the administration tasks of a data warehouse application, and I was asked to define a method to determine the growth of the data warehouse (capacity planning).
June 1, 2000 I was asked to define a method to determine the growth of our data warehouse. How can I achieve this in the most accurate way?

Are expert systems on the decrease? Ten years ago they seemed to be the next new thing.
May 1, 2000 Are expert systems on the decrease? Ten years ago they seemed to be the next new thing.

We are looking at Oracle Data Warehouse builder.
May 1, 2000 Could you could point me to any evaluations on Oracle Data Warehouse Builder?

We are working on a data mart for a risk analytics business.
May 1, 2000 In order to achieve good query performance, which report on these facts, we are thinking of calculating and storing them in a...

Are there any cases where the dimensional table is larger than the fact table?
May 1, 2000 Are there any cases where the dimensional table is larger than the fact table?

I am interested in finding benchmark tests that have compared ETL tools.
May 1, 2000 Are there any benchmark tests that have compared ETL tools?

How does knowledge management relate to data management?
May 1, 2000 How does knowledge management relate to data management?

We are a startup company aiming to develop a product to mine the network traffic for business intelligence.
April 1, 2000 Do you think it is a clever approach to extract information from the network traffic and let users combine it with data they...

My question pertains to slowly changing dimensions. We need to keep history so we plan on inserting a new row when the dimension changes.
April 1, 2000 What are some techniques to capture a change on the OLTP database and apply that change to the warehouse?

Given the often predicted growth in demand for data warehousing, data mining and business intelligence capabilities as a result of the e-commerce boom,
April 1, 2000 Given the individual strengths and positions of SQL, Oracle and IBM in the database world, which certification program would...

We want to build a data warehouse in our organization by using an ERP application as the main source.
April 1, 2000 I read in an article that using ERP as the main source and doing dimensional modeling for data warehousing is difficult. Is...

I was wondering what you recommend as a good tool to build a data mart or star schema.
April 1, 2000 What would you recommend as a good tool to build a data mart or star schema?

I'm the marketing guy, not the DBA.
April 1, 2000 I want to begin collecting e-mail addresses for newsletters, but my DBA is resisting an e-mail address-only database. How do...