A middleware implementation of active rules for ODBMS

Throughout many research and development projects for active rule systems, active rules are implemented with different syntax and semantics. It becomes one of the stumbling blocks to apply active database systems especially in networked heterogeneous multidatabase environments. Utilizing the recent development of CORBA and ODMG standards, a middleware approach to provide active rule systems for heterogeneous ODBMS is presented in this paper. The active rule system described is applied for integrity maintenance of spatial objects. According to the events included in application programs, the active rules represented in ECA type are inserted into the program by a preprocessor. One advantage of this compile approach is that the preprocessed program can be compiled and executed without the overhead of runtime monitoring. For the changed rules after compilation, a run time interpreter is included in the executable program.