Distributed result set iterator: a design pattern for efficient retrieval of large result sets from remote data sources

摘要

Retrieving large amounts of information over wide area networks, including the Internet, is problematic due to issues arising from latency of response, lack of direct memory access to data serving resources, and fault tolerance. As both the public and industry require an ever increasing amount of data to be transferred in a timely fashion, we face the challenge of providing the technology to meet these consumer-driven demands. We must be able to deliver large amounts of information promptly with immediate feedback to user requests. In addition, this must be achieved in a robust manner while conserving computing resources. This paper describes a design pattern for solving the issues of handling results from queries that return large amounts of data. Typically, these queries would be made by a client process across a wide area network (or Internet) to a relational database residing on a remote server. The solution is discussed in detail in this paper and has recently been incorporated into the framework of a commercial software product developed at Oracle Corporation.