Study And Implementation Of Query Mechanism In EDBMS

As the core technique of mobile-computing, mobile-commerce and informative electrical appliances, the Embedded Database Management System appears recently which is a newly data management technology. The EDBMS which based on the mature technology of DBMS and aimed at the idiographic embedded system and device, implements the embedded system data store, data organize, data management and data exchange with the background data source according practical requirement. The particularity and the advanced technology of the embedded system and EDBMS are introduced firstly. This dissertation proposes that the capability of EDBMS is decided by the spending of system resource but not the traditional numbers of I/O operations according to the peculiarity of embedded system and the appliances requirement. In this dissertation, the system architecture of the EDBMS based on the EMS memory is pinpointed. Those pivotal techniques in the development of the system, including query process and query optimization are further discussed. In view of the embedded system environment and its application characteristics, the embedded database system provides one set of query subsystems. Different EDBMS has its own way of query processing. An object-oriented query mechanism has proposed in this dissertation, which is similar to the SQL and can query data from the database rapidly and effectively. Not only enhance the entire database performance, this method also can provide the convenience to the developers of embedded application systems. The execution of queries, when all data is present in memory, is very fast, compared with the time for query execution in a traditional RDBMS. But EDBMS even more increases the speed for query execution by applying several optimizations: using indices, inverse references and query parallelization.