A mathematical model for distributed free space

To have fast response time is often a requirement for a data base system especially in the on-line environment such as inventory control, stock quotation or hotel/airline reservation. This requirement for fast response time can be easily obtained by carefully organizing the file at loading time. Due to subsequent insertions, the file structure designed with fast response time would be damaged because insertions were stored in overflow area. As more insertions are added, the response time will be lengthened since accessing records in overflow area takes more time than in home area. When the response time exceeds the tolerance limit that a user can stand, a reorganization is required. In general, reorganization of a file is a costly and time-consuming job and should be avoided as much as possible. In order to maintain a fast response time and to avoid frequent reorganizations, a technique called "distributed free space" 10 within home area was introduced.