Tsae-Feng Yu

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This paper describes Continuous Queries (CQ) in Oracle RDBMS, a feature that incorporates stream and complex event processing into an RDBMS, the first such attempt in commercial databases. The feature is based on the concept of query difference and allows us to monitor real time changes to the query as the result of changes to its underlying tables. The(More)
For achieving interoperability among heterogeneous computing systems, the Object Management Group (OMG) has adapted the Common Object Request Broker Architecture (CORBA) and the use of an Interface Definition Language (IDL) for specifying object properties and operations which encapsulate the data and programs of heterogeneous systems. This paper describes(More)
The main objective of a virtual enterprise (VE) is to allow a number of organizations to rapidly develop a working environment to manage a collection of resources contributed by the organizations toward the attainment of some common goals. One of the key requirements of a tirtua.1 enterprise is to develop an information infrastructure to sup port the(More)
This paper describes an integrated information modeling language called NCL which combines the features of IDL and EXPRESS as well as the features of the association types and knowledge rule speciications ooered by the Object-oriented Semantic Association Model (OSAM*). In this language, frequently used constraints are speciied by keywords, association(More)
To make effective use of distributed systems acting together to form a virtual enterprise, global coordinated operations must be possible. Such operations may be mere queries or complex update operations. In this paper, we describe an existing system at the University of Florida which not only models a Virtual Enterprise using a common object-oriented(More)
A heterogeneous information system can be built on a large number of component systems which are interconnected by a LAN or WAN. The data stored in these component systems are likely to have very diierent naming, structural and semantic representations. The querying facility of the information system needs to couple with an information mediation facility to(More)
The main objective of a virtual enterprise (VE) is to allow a number of organizations to rapidly develop a working environment to manage a collection of resources contributed by the organizations toward the attainment of some common goals. One of the key requirements of a virtual enterprise is to develop an information infrastructure to support the(More)