Tim@cis.upenn.edu (Tim Finin) (11/13/86)
DBIG Meeting
10:30 Friday November 14th
554 Moore School
University of Pennsylvania
DEVELOPMENT OF AN OBJECT-ORIENTED DBMS
David Maier
Oregon Graduate Center
and
Servio Logic Development Corp
GemStone is an object-oriented database server developed by Servio Logic
that supports a model of objects similar to that of Smalltalk. GemStone
provides complex objects with sharing and identity, specification of
behavioral aspects of objects, and an extensible data model. Those features
came with the choice of Smalltalk as a starting point for the data model and
its programming language, OPAL. However, Smalltalk is a single-user,
memory-based system, and requires significant modifications to provide a
multi-user, disk-based system with support for associative queries objects
of arbitrary size.
This presentation begins with a summary of the requirements for a database
system to support applications such as CAD, office automation and knowledge
bases. I next introduce the Smalltalk language and its data model, showing
how they satisfy some of the requirements, and indicating which remain to be
satisfied. I will outline the approach Servio took on the remaining
requirements, describing the techniques used for storage management,
concurrency, recovery, name spaces and associative access, as time permits.