Distribution design is one of the most important steps in distributed database design and its research is active. This thesis proposes a methodology for distribution design and then implements a design support system called DBDD. The methodology consists of three phases such as (i) schema analysis, (ii) fragmentation, and (iii) allocation. In the schema analysis phase, all the table names are acquired from a global relational schema. In the fragmentation phase, fragments are generated according to transaction retrieval patterns. Furthermore, DBDD enhances the design quality allocating fragments progressively. A case study is illustrated to demonstrate the practical usefulness of the DBDD.
