Virtual Database Technology for Distributed Database in Ubiquitous Computing Environment

In this paper, our research objective is to develop a database virtualization technique in order to let data analysts or other users who apply data mining methods to their jobs use all ubiquitous databases on the Internet as if they were recognized as a single database, thereby helping to reduce their workloads such as data collection from the Internet databases and data cleansing works. In this study, firstly we examine XML schema advantages and propose a database virtualization method by which such ubiquitous databases as relational databases, object-oriented databases, and XML databases are accessed as if they all behave as a single database. Then, we show the method of virtualization of ubiquitous databases that can describe ubiquitous database schema in a unified fashion using the XML schema. It consists of a high-level concept of distributed database management of the same type and of different types, and also of a location transparency feature. Next, we discuss about the development of a common schema generation method and propose the virtual database query language for use in the virtualized ubiquitous database environment. Finally, we propose a database incompatibility trouble-recovery technique for use in a virtualized ubiquitous database environment.