Journal of Electrical Engineering and information Science
- 제1권1호
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- Pages.164-172
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- 1996
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- 1226-1262(pISSN)
A Horizontal Partition of the Object-Oriented Database for Efficient Clustering
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Chung, Chin-Wan
(Department of Information and Communication Engineering, Korea Advanced Institute of Science and Technology) ;
- Kim, Chang-Ryong (Department of Information and Communication Engineering, Korea Advanced Institute of Science and Technology) ;
- Lee, Ju-Hong (Department of Information and Communication Engineering, Korea Advanced Institute of Science and Technology)
- 발행 : 1996.03.01
초록
The partitioning of related objects should be performed before clustering for an efficient access in object-oriented databases. In this paper, a horizontal partition of related objects in object-oriented databases is presented. All subclass nodes in a class inheritance hierarchy of a schema graph are shrunk to a class node in the graph that is called condensed schema graph because the aggregation hierarchy has more influence on the partition than the class inheritance hierarchy. A set function and an accessibility function are defined to find a maximal subset of related objects among the set of objects in a class. A set function maps a subset of the domain class objects to a subset of the range class objects. An accessibility function maps a subset of the objects of a class into a subset of the objects of the same class through a composition of set functions. The algorithm derived in this paper is to find the related objects of a condensed schema graph using accessibility functions and set functions. The existence of a maximal subset of the related objects in a class is proved to show the validity of the partition algorithm using the accessibility function.
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