The implementation and evaluation of an extended relational database called ADAM (advanced database abstraction mechanism) are discussed. A browsing algorithm is developed for composite objects to support reuse of the objects. The algorithm takes advantage of aggregation hierarchies to select related composite objects and to order them based on the two measures, i.e. the relative difference of matching components (RDMC) and the number of nonmatching components (NNC). The algorithm has been implemented and various kinds of experiments have been carried out with a standard integrity constraint database. The results show that the CPU time roughly linearly depends on the number of selected objects. Around 90% of the CPU time is consumed in calculating RDMC and NNC. RDMC is more sensitive to retrieval conditions than NNC.>

In order to achieve consistent management of design and analysis of engineering objects, data in engineering applications are required to be manipulated in an integrated manner. Engineering data comprise attributes, structural and pictorial information. ADAM uses the relational model as a basis for representing attributes information and structures of engineering data. As for pictorial information, ADAM data definition language provides figure specification parts where pictorial notations of instances are represented in terms of functions in computer graphics. In this paper, we observe engineering data and give some considerations on them. Four essential features of engineering data are discussed. Data definition and manipulation facilities of ADAM are presented. Instances with arguments are introduced for managing complex structures of engineering data and repeated appearances of similar objects. A graphic algorithm is discussed, which allows users to retrieve pictures in any intended details.