Abstract:
In Multidatabase Systems (MDBS), pre-existing autonomous local database systems that manage by heterogonous Database Management System (DBMS) in distributed environment are integrated together. Consequently, in such surroundings, global query optimization should be considered to achieve the overall system performance. Concurrently, security consideration is enlarged greater than before. Therefore, autonomous nature of such MDBS causes additional challenges in optimizing query process as well as offering adequate security features. Although, the majority of algorithms that have been suggested and used for optimizing query in such context are lacking of security aspects. Thus, this study proposes a security enhancement to query optimization algorithms.
The proposed security enhancement considered access control mechanisms, which maintain the database confidentiality and integrity, as a crucial security aspect that ought to associate with query optimization process. Moreover, an appraisal experiment is conducted using ORACLE-9i in order to confirm the feasibility and robustness of such enhancement. The experimental results shown that the enchantment approach is entirely adequate and promising, particularly in term of estimating local cost parameters. Furthermore, statistical measures confirm that the derived cost formula is significant
