Existing visual query languages that have been designed for graphical user interface and translated into existing text-based query language such as SQL. Many database users desire to have not only user friendly designed visual query language, but also fast response for query results. In this respect, visual query languages need to more efficient ways of query processing as in the conventional text-based query languages.
This paper proposes the mapping rules that translate Object Query Diagram(OQD) to an object-oriented algebra for the efficiency of visual query language's query processing. OQD is the visual query language for object-oriented database systems, which has been proposed by Kwak and Moon at KAIST. The object-oriented algebra has been proposed by G.M. Shaw at Brown University. The mapping rules are classified into three categories. The first is the basic operator mapping rule, which is one-to-one translation of OQD operator to the algebra. The second is the semantic mapping rule, which is used to translate visual information and OQD semantics to the algebra. The third is the advanced operator mapping rule, which is used to translate applied OQD operator semantics to the algebra. The translator in this thesis is implemented in C language and runs on the MS-DOS environment.
