Execution of distributed queries in the web environment

Abstract

Database query processing is one of the fundamental issues in data engineering, particularly when more and more databases become distributed over the Internet in the last decade. There have been several approaches to the problem of distributed query processing (DQP), some were successful in the client-server environment but not so in an environment with heterogeneous and autonomous databases. The challenge relies on the nature of the Internet and the Web that pose many difficulties to the problem in hand. In this paper, we propose a model that uses an XML standard and its equivalent in-memory data structure to achieve data sharing, and invokes XML Web services in asynchronous mode to allow local database management systems to efficiently process local data. This approach, like XJoin, allows progress to be made even when data sources experience delays. It builds a layer on top of existing database management systems to minimize the complexity and cost for processing distributed queries that is critical for making such a method practical.