ylfink@water.waterloo.edu (ylfink) (09/06/88)
DEPARTMENT OF COMPUTER SCIENCE UNIVERSITY OF WATERLOO SEMINAR ACTIVITIES COMPUTER SCIENCE COLLOQUIUM - Thursday, September 8, 1988 Dr. Hans-Peter Kriegel, University of Bremen, West Germany, will speak on ``Spatial Access Methods based on Dynamic Hashing''. TIME: 3:30 PM ROOM: DC 1302 ABSTRACT In order to handle spatial data efficiently, as required in computer aided design and geo-data applications, a database management system needs an access method that will help it retrieve data items quickly according to their spatial location. We will present a classification of existing spatial access methods and show that they use one of the following three techniques: clipping, overlapping regions, and transformation. From a practical point of view we provide a tool box supporting simple design of a spatial access method for a given point access method using one of the above techniques. We analyze the technique of transformation in more detail and show that our new concept of asymmetric and non-orthogonal partitioning is more retrieval efficient than the traditional symmetric and orthogonal approach.