Databases Reference
In-Depth Information
Sometimes business input is solicited to address data questions. This is
not well received because everyone is so busy pulling data and producing
reports for the upcoming quarterly management meetings. Therefore, the ETL
developers just forge ahead and don't bother the business with questions.
After a short development time, data is loaded and deemed ready for use.
However, now that the business begins to look at the data, serious problems
are identified. It turns out that many of the assumptions used to process the
data were not valid. While the team met the short timeframe, the data is not
usable.
After a great deal of finger pointing, a team is put together to conduct a
review. The purpose is to determine whether it would be better to clean it up
or start over. Because very little was documented and there was no cohesive
system design for the ETL processes, it is determined to simply start over. This
does not mean starting from scratch — the project team learned a lot about the
data and about ETL development. Before diving in to build more processes, a
joint business and IT data governance team is formed to study the data and
develop standard definitions and guidelines regarding how data elements are
to be handled. With this joint team to help answer data questions, the new
project includes time to develop complete specifications. The project is going
much better and the preliminary results are good. The data will be trustworthy
and help meet the business requirements.
Summary
The ETL system is at the heart and soul of the data warehouse and must be
driven by detailed requirements for the data. Taking the time to understand
and document these requirements helps to design and develop a robust pro-
duction system. A lot of work is done by the ETL system to extract, transform,
and load the database. This chapter introduced the basic functionality of these
steps.
While much of this work is technical in nature, the business perspective
must still be represented. Business representatives must be involved in defining
business rules for handling the data and a test plan and detailed test cases.
Once development begins, the business must continue to support the ETL
developers by answering questions about the data promptly and enabling
cross-functional group decisions when necessary.
The business needs to continue to provide input and guidance to the tech-
nical team members to ensure that the data is prepared properly. Continued
partnership between business and IT can help each data warehouse project to
successfully load high-quality data. With the data loaded, it is time to take a
closer look at how it can be used. The next chapter focuses on delivering data
into the hands of the business community.
