This approach considers the structure version, which is
a view on a temporal data warehouse valid for a given time interval. The proposed
system is able to represent successive versions of structures, and provides transformation
functions to map data from a structure version to a different one.
In Eder et al. (2001), the authors propose an architecture for temporal data warehouse
systems which allows the registration of temporal versions of dimension data, and
the transfer of data between different temporal versions. In this work, the authors
extend the model presented in Eder and Koncilia (2001) to represent also modifications
at the schema level, such as the insertion of a new dimension level (e.g., the
new dimension level quarter inserted between month and year).
In Marian et al. (2001), the authors present a change-centric method for managing
versions in Web warehouses of XML data. These warehouses contain sequences
of snapshots of XML documents coming from the Web. The approach is changecentric
because the proposal focuses on changes (deltas). At each point in time, the
last version of a document and the sequence of completed deltas (similar to logs
of database systems) are stored. In this work, the time of a document version is
Temporal Semistructured Data Models and Data Warehouses 28
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