Query classification in object-oriented engineering design systems

Abstract A query model for object-oriented engineering design systems exhibits characteristics that are quite different from those found in relational models. An engineering query model should take into account the fundamental concepts and requirements of interactive engineering applications that are not found in traditional applications. For example, engineering systems deal with large volumes of data of high complexity, with recursive structures and rich semantic properties. Similarly, engineering systems require the support of ‘long transactions’, as opposed to the ‘short transactions’ found in traditional relational-database systems. These differences have an interesting effect on the complexity of and strategy for query evaluation in engineering systems. The paper provides a framework for the classification of queries in engineering design systems. Engineering queries are classified into several categories on the basis of their semantics and complexity, and the impact of these queries on the architecture of an object-oriented engineering design system is shown.