Using Active Rules to Maintain Data Consistency in Heterogeneous Database Systems

• Main Authors: Liu, Jung-Kwi, 劉榮貴
• Other Authors: Shi-Ming Huang
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/40057821105496884609

碩士 === 大同工學院 === 資訊工程學系 === 84 === The heterogeneous environment is emerging in the current information systems. Within this situation, it is desirable whenever maintain consistency across databases, i.e., to ensure that they do not contradict each other with respect to the existence or value of real-world entity. Maintaining data consistency is particularly difficult in heterogeneous database systems (HDBSs). This is due to the schematic and operation heterogeneity problem. Active rules have been used to deal with this complex data consistency problem. The aim of my research is to see how the active rules can be used to maintain data consistency in HDBSs. The author examine the active rules in the different types of autonomous local database systems with different integrity constraint mechanisms. Much current research declare synonym attributes to maintain the data consistency within HDBS. This is called equivalence level data consistency. In this thesis, the author shows that active rules can maintain data consistency not only in equivalence level, but also in different semantic level and instance level data consistency. The syntax of my active rules includes rule body and coupling model. The coupling model of active rules provide more flexibility and semantics to define complex active rules. Defining appropriate coupling model of related active rules will also reduce the problem of rule conflict resolution. The author also describes a new global transaction mechanism which integrates active rule processing and database data transaction. A prototype active HDBS has been developed to simulate my hypothesis. The result of my investigation has shown that it is a good solution by using active rules to maintain data consistency in HDBSs.