Because of the formidable obstacles to realizing the ideal distributed database, DBMS vendors have taken a step-by-step approach to databases and networking. They have focused on specific forms of network database access, data distribution, and distributed data management that are appropriate...

In distributed database systems, relations are replicated and fragmented at multiple sites to ensure easy availability and greater reliability. This leads to an exponential increase in the possible alternatives available for selecting the set of sites, constituting a query plan, for processing....

A large number of queries are posed daily against the distributed databases spread across the globe. Query processing strategies are used to generate efficient query plans for these queries. The number of such query plans increases exponentially with the increase in the number of involved sites...

Distributed data - data, processed by a system, can be distributed among several computers, but it is accessible from any of them. A distributed database design problem is presented that involves the development of a global model, a fragmentation, and a data allocation. The student is given a...

In this paper we present an analysis of the problem of determining optimal policies for updating distributed materialized views. We demonstrate the general application of materialized views, and define the concept of materialized view currency and allow a query to specify its currency...

Romania has a huge tourist’s potential, but currently it is too little valued and exploited. As a result, one of the strategic developments of the economy aimed the tourism industry. The strategic decisions are based on different trends obtained from soph

A possibility of a temporary disconnection of database service exists in many computing environments. It is a common need to permit a participating site to lag behind and re-initialize to full recovery. It is also necessary that active transactions view a globally consistent system state for...