Answer Set Programming Representation for E-R Model

As a well-known semantic data model, E-R model is widely applied in the database design phase. But, E-R model itself has some defects, and these defects restrict the further applications of the model. Currently there are two main approaches about the improvements for E-R model. One is based on the graphical representation and the other is based on the description logic representation. Whereas, the former still has not automatic reasoning capability, and the latter has some shortcomings such as the weak representation capability and the insufficient compatibility with relational database. To overcome these shortcomings, a novel method is proposed which utilizes the answer set programming to represent E-R Model. Firstly, E-R schemata corresponding to the databases are distinguished as the basic and the extended types, and then their syntax and semantic definitions are accomplished. Secondly, the answer set programming is utilized to accomplish the representations of the two types of the schemata above. Finally, the correctness of these representations is proved. The proposed method not only supplies a new logic representation approach for E-R model, but also has some obvious advantages over the two common used improvement approaches. More importantly, the results of this paper make it possible to apply E-R model to realize the semantic interoperability among heterogeneous databases.