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In traditional DBMS, once transaction updates have been
committed and permanently installed, the previous values of
data usually are discarded. In more advanced applications,
especially those in which a database has to support the design
of a manufactured product, versions of objects have to be
managed, have to be managed, i.e., to keep different status of
the same data. This requirement is inherent in applications
that are exploratory and evolutionary. Moreover, versions can
be used provide a different alternatives of the same data. That
is particularly useful in design applications, where different
designers might need to explore different design choices in
parallel. Version control in the multimedia document creation
environment is similar to that in any design environment. In
this thesis, we design and implement the query language for
multimedia database version control, including historical
versions and alternative versions. Basically, in order to
maintain a consistent configuration of objects, we have to
consider the effect of different operations to the versions,
including deleting or updating a sharing object, change
notification, change propagation and inheritance. Those are
also the main design issues of version control. In the past
three years, based on the object-oriented data model, Prof.
Chang and her students have designed and implemented a QBOE
multimedia database system. In this thesis, we extend QBOE with
version control; that is, we design and implement the query
language for multimedia database version control. Moreover, we
consider data of types text, drawing, image, audio, animation
and video.
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