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1987 IEEE Third International Conference on Data Engineering (1987)
Los Angeles, CA, USA
Feb. 3, 1987 to Feb. 5, 1987
ISBN: 978-0-8186-0762-2
pp: 138-148
Martin Hardwiek , Department of Computer Science, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
George Samaras , Department of Computer Science, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
David L. Spooner , Center for Interactive Computer Graphics, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
ABSTRACT
Entities such as mechanical assemblies are recursive when they contain other assemblies at a lower level of detail. In this paper we show how recursive CAD entities can be manipulated using an extended projection function. The new function finds nested sub-entities within entities that are modeled as trees of aggregations and generalizations. It allows these sub-entities to be found using expressions that are independent of the complexity of an entity's data structure. We describe the new function, its relationship to the transitive closure function, and its implementation in a CAD database system.
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CITATION

M. Hardwiek, G. Samaras and D. L. Spooner, "Evaluating recursive queries in CAD using an extended projection function," 1987 IEEE Third International Conference on Data Engineering(ICDE), Los Angeles, CA, USA, 1987, pp. 138-148.
doi:10.1109/ICDE.1987.7272367
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