Completing CAD data queries for visualization

A system has been developed permitting database queries over data extracted from a CAD system where the query result is returned back to the CAD for visualization and analysis. This has several challenges. First, CAD data representations use complex object-oriented schemas and the query language must be object-oriented too. Second, the query system resides outside the CAD system and must therefore use standardized data exchange formats for interoperability with the CAD. ISO STEP standard exchange formats are used for the exchange. Third, a CAD system cannot import an arbitrary object structure but places restrictions on the imported objects to be acceptable. Therefore, the query system must complement the query results in order to produce an acceptable CAD model, called the model completion of the query. These problems have been solved using an extensible object-relational query processor. The system also supports queries combining CAD data with data from other data sources.