Data Warehouse Maintenance, Evolution and Versioning - Data Warehousing Design and Advanced Engineering Applications - page 187

CONCLUSION REFERENCES

Bellahsene, Z. (2002). Schema evolution in data
warehouses. Knowledge and Information Systems ,
4 (3), 283-304. doi:10.1007/s101150200008

Maintenance is an important aspect in the data
warehouse domain. Typically, data warehouse
systems are used in a changing environment thus
the need for evolving systems is inevitable. This
chapter provides some simple, but yet illustrating
examples that motivate the need for data ware-
house maintenance.
Founded on basic data warehouse concepts, the
levels of data warehouse maintenance are intro-
duced. Data warehouse structure may change on
the schema (i.e. dimensions and categories) and
instance (i.e. dimension members) level. Not only
the structure elements themselves, but also the re-
lations between them may change. When keeping
track of structure changes, one has also to decide
whether to use an evolutionary or versioning ap-
proach. Keeping available prior versions may for
instance be necessary for legal reasons. Besides
managing these structural changes, another im-
portant aspect of data warehouse maintenance is
dealing with the impact of structure changes on
the cell data. Modifications of structure data may
corrupt the structural and/or semantic consistency
of the associated cell data.
There are several approaches dealing with
the data warehouse maintenance problem. One
of them, namely the COMET metamodel for
Temporal data warehouses, is presented in some
details. Several other approaches addressing the
data warehouse maintenance problem are shortly
introduced. After their introduction, some of the
presented approaches are compared with respect
to several features. Approaches dealing with
problems related to data warehouse maintenance
are presented to mark the boundaries of this re-
search area.

Blaschka, M., Sapia, C., & Höfling, G. (1999). On
schema evolution in multidimensional databases.
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Body, M., Miquel, M., Bedard, Y., & Tchounikine,
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Dynamic Information Warehouse, K. A. L. I. D.
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Eder, J., & Koncilia, C. (2001). Changes of di-
mension data in temporal data warehouses. In
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Eder, J., Koncilia, C., & Morzy, T. (2002). The
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Eder, J., Koncilia, C., & Wiggisser, K. (2006).
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