On CAD databases

CAD data has some unique characteristics that make its management difficult. The design of a CAD object usually has a complex structure that involves large volumes of data. Besides, in many CAD situations, the designed object has many aspects of data to be stored and may be updated later. It may also be used in the design of a more complex objects, and may in turn consist of lower level components. When a lower level component is changed, the higher level component that contained it should either be changed automatically or become invalid. All these different aspects of data need to be stored and dealt with properly in an integrated environment that can accessed by different CAD utilities so that the cost of storing, maintaining and accessing these objects is minimum. Traditionally, CAD data is handled with file systems rather than database systems. In this paper, we discuss how various database technology can be used to support the storage and access of large volumes of CAD data with a complex structure.