New features for a relational database system to support computer aided design

摘要: Data management is a significant problem in Computer Aided Design (CAD) systems which handle large volumes of data variety forms. However traditional database have not been widely used CAD because they are hard to use and do offer some needed functions. The purpose this research develop features that can be added relational make them more useful for supporting CAD. We ran an experiment prototype system, INGRES, was store Very Large Scale Integrated circuit (VLSI) design data, perform typical retrieval operations. INGRES awkward context much slower than specially designed programs. remainder thesis investigates several additions suggested by the would it easier efficient. We augmented query language QUEL with append* command expressing transitive closure queries, retrieve hierarchically structured VLSI designs. Processing issues discussed implementation test results given. An indexing structure called R-tree presented overlapping non-point spatial objects according their locations multi-dimensional space. R-trees residing on paged secondary memory, suitable as access method. Specialized applications like often assign meaning cannot exploited general-purpose system optimize structures processing. We outline way user-supplied semantic routines supply information purpose. CAD composite entities made up many parts. discuss three ways represent such composites database: abstract type arrays, means built-in array types, nested relations. All we studied could current systems, only but also other involving highly data.