5/22/1998
3:00pm-5:00pm
ECOT 831
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A Multistate Service Based on Deltas and Its Application to Support Collaborative Work Applications
Computer Science PhD Candidate
In many applications, the representation and management of change is of primary
interest, often being as important as the representation and management of
state. The concurrency control policies of database management systems, which
are focused on the maintenance of single consistent states, present an obstacle
to the support of such applications. The research presented here has resulted
in the development of theory to support new data storage techniques that
overcome such obstacles without losing the other benefits provided by database
systems. This theory, called Heraclitus[OO], is centered on the use of delta
values, which capture state changes as first class objects available for
manipulation by applications and users. The theory has been applied in the
development of the H2O/SST data storage manager.
In the general area of cooperative work support, authoring systems and related
applications are in particular need of support for flexible management of
change as well as support for the resolution of resulting conflicts. To this
end, this research has also developed an architecture by which H2O/SST can be
used to support such applications. This architecture, called Coral, is designed
to allow for the incorporation of application specific policies regarding the
management of change and conflict. The principles of Coral have been
demonstrated through the implementation of a prototype authoring system.
Additionally, the development of applications based on Coral and H2O/SST is
illustrated through an example system design. This system design includes the
design of procedures to support authoring through delta values and the
specification of particular delta values to support text documents.
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