An Extended Relational Database System and It's Application to Management of Logic Diagrama

An extended relational database and its application to VLSI data management are described. The following shortcomings mainly arise when we try to apply conventional DBMSs to management of engineering data : lack of facilities to support various data types, a design hierarchy, version control and efficient access to design data. We have extended the relational data model by supporting (1) a set of graphics functions that bridge relational data structures to graphics representations, (2) a special data type that allows a designer of the database to model the design hierarchy ( including versions ) explicitly. Ordinary relational databases appear to be too slow to be used on-line in a design process. Our hypothesis is that it does not come from the nature of the relational model, but rather internal access mechanisms. We have developed our system in such a way that data on a design object are stored as interrelated collections of records and are manipulated as a logical group. As a result, our system offers sufficient facilities and performance for interactive use of design data at design system level.