Hash-based scalable distributed data structures (SDDSs), like LH * and DDH, for networks of intcmonnected ampllters (multicomputers) were shown to open new perspectives for fik management. We prcpose a family of ordered SDDSs, called P, providing for ordered and dynamic files on mutticomputers, and thus for more etlicknt pmeessing of range queries and of ordered traversak of files The basic algorithm termed RP*K builds the file with the same key space partitioning as a Etree, but avoids indexes through the use of multi&. The a&nithms, RP*c and RP*s enbance throughput for faster network adding the indexes on clients, or OII clients and sexve-rs, while eithe-r decmsing or avoiding multicast. Rpo files are shown highly efficient with access performance exceeding traditional files by an order of magnitude or two, an & for non-range queries very close to LH*. 1.

As with other distributed database systems, it is important in an Active Object Oriented Knowledge Base Management System (AOOKBMS) to be able to execute distributed queries efficiently and cost effectively. In this paper, we show how this task is being tackled in an ongoing project at the University of Florida dealing with Virtual Enterprises (VE). This project uses an AOOKBMS to not only describe a common view of the VE's data and processing capabilities, but to also support distributed query optimization and processing. Through the use of wrappers this system allows the distributed execution of a query defined in an Object Query Language. It can be executed on heterogeneous systems that may include Object Oriented and Relational databases as well as non-database oriented systems. The results of this distributed processing is then combined and presented in a single uniform result, thus supporting the concept of a truly Virtual Enterprise. In this paper we cover how query optimization...