Page 235 - DCAP603_DATAWARE_HOUSING_AND_DATAMINING

Unit 12: Metadata and Warehouse Quality

notes
figure 12.1(b)

12.2.4 Why two tools for Meta Data Management?

There are continuing debates in the industry about whether technical and business meta data
should be maintained in the same meta data store or kept separate. This debate looks at meta
data from the wrong dimension. Meta data should be viewed from the perspective of the person
using it not simply from the type of meta data it is. In general, technical staff employ technical
meta data during warehouse development and maintenance. They also need access to certain
types of business meta data. Examples include the common business model when discussing
information requirements with business users and BI tool business views when analyzing the
impact of warehouse design changes. Business users, on the other hand, employ business meta
data as an aid to finding the business information they require in a warehouse; but they also use
high-level technical meta data when trying, for example, to relate decision processing results to
the source data used to create the results.
There is a strong argument in favor in of the deployment of the two types of meta data management
tools: a GUI- or Web-based tool (a meta data hub) for technical staff when developing and
maintaining the data warehouse and a Web- based tool (a business information directory) for
business users when employing decision processing tools and applications. The reason for this
separation is that the usage, architecture and interfaces for the two types of meta data user are
completely different. There does, however, need to be a link between the two types of tool. Users
of a business information directory need to be able to drill through from a business information
directory to the technical meta data maintained by a meta data hub. To facilitate this drill- through
facility, the two types of meta data management tools might employ a common meta data store.
The approaches and products are targeted at technical users and at providing support for one
or more requirements of a meta data hub. For this reason, in the remainder of this article, we
will focus on the architecture and requirements of a meta data hub. It is important to point out,
however, that vendors are also working on meta data management tools for business users.
These tools support the concept of a business information directory and are being integrated into
a Web-based interface known as an information portal.

Task Discuss the role of Meta data repository in a data warehouse? How does it
differ from a catalog in a relational DBMS?

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