View Selection and Materialization - Data Warehousing Design and Advanced Engineering Applications - page 125

Figure 5. The multi view materialization matrix

the set of materialized views. Re-computing the
entire MVMG for each query submitted to the
data warehouse can become extremely expensive
and time consuming, therefore we've created the
option to periodically re-compute all views in the
MVMG and remove infrequent views.
In addition, the refresh function is also used
to update the set of materialized views in the data
warehouse to reflect the changes made to the
original data sources.
MATUN provides the option to generate query
statistics automatically from a given data source

based on the time it takes to answer a query and
the algorithm used to estimate the number of disk
pages needed to store the result set. However,
these statistics are often misleading because of
caching mechanisms used by the data source and
optimistic estimations.

RELATED WORK

A great deal of studies has been performed in
the area of view selection problem in data ware-

Figure 6. MATUN user interface