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Recently, as the rapid advances in Internet technologies, there have been many related tools and applications developed, including improvement in browsers, enhancement in server functionality, and also standardization of network protocols. These technology developments have influenced the database architecture, which evolves from centralized ones, to distributed ones, and then to networked ones. While having its own advantages, a network database also encounters the problem of storage and retrieval for decentralized data. Specifically, how to perform a join operation efficiently is a difficult problem since the data transmission over the network is expensive and how to minimize the transmission cost for performing a join is intrinsically hard to solve. Such a problem is even more important and difficult to resolve when a multi-join is being carried out. In this paper, we shall investigate the problem of multi-join execution in a network database and develop a schedule that is able to not only effectively decompose a multi-join into a proper join and semi-join sequence but also efficiently conduct its execution. In addition,w e will utilize related technologies, including Java applets, JDBC, etc, to implement a Web-base network database. In this network database system, users can access the data and issue the multi-join query through a proper Web interface, and the system will take full advantage of the scheduler devised to perform a multi-join query so as to improve the overall system performance. Due to the increasing popularity of Internet, the use of multi-join is expected to be even more frequent, and its execution, without proper scheduling, is becoming the bottleneck of a network database. In view of this, we believe this study is very timely and the results are of both theoretical and practical importance.
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