Developing a meta data repository solution is not an
event—it is an evolution. It starts with the first BI
decision-support initiative and continues to evolve
on an ongoing basis. Whenever new business data
is added to the BI target databases, new meta data
is added to the meta data repository (for example,
names, definitions, and domains of the new
business data). Whenever new functionality is
added to the BI applications, new meta data is
added to the meta data repository (for example,
calculations and reconciliation totals for the new
functions).
Be prepared to develop two types of meta data
repository interfaces:
- Access interface for business people and
technicians
- Tool interface for sharing meta data between
the meta data repository and the tools where
meta data is originated
Be sure to understand the import/export features of
the tools from which you will extract meta data, for
example, CASE, ETL, OLAP. Depending on how
much or how little commonality there is among the
tools, you may have to write several different tool
interface programs.
The estimated size of a meta data repository could
reach 5 percent of the total size of BI target
databases, if done correctly and diligently.
Keeping the meta data repository up to date and
synchronized with other tools, databases, and
programs is a challenge. It will require collaboration
from all stakeholders on all BI projects. The bigger
challenge is to get the operational systems people
to communicate any changes to their source data
immediately. Changes to source data may also
affect the ETL process and the design of the BI
target databases.
Remember that for every day of coding, you will
probably spend at least three days on testing.