Optimized query planning of continuous aggregation queries in dynamic data dissemination networks

Continuous queries are used to monitor changes to time varying data and to provide results useful for online decision making. Typically a user desires to obtain the value of some aggregation function over distributed data items, for example, to know (a) the average of temperatures sensed by a set of sensors (b) the value of index of mid-cap stocks. In these queries a client specifies a coherency requirement as part of the query. In this paper we present a low-cost, scalable technique to answer continuous aggregation queries using a content distribution network of dynamic data items. In such a network of data aggregators, each data aggregator serves a set of data items at specific coherencies. Just as various fragments of a dynamic web-page are served by one or more nodes of a content distribution network, our technique involves decomposing a client query into sub-queries and executing sub-queries on judiciously chosen data aggregators with their individual sub-query incoherency bounds...

• Type: Conference
• Year: 2007
• Where: WWW
• Authors: Rajeev Gupta, Krithi Ramamritham
• Keywords: Continuous Aggregation Queries, Continuous Query Cost, Internet Technology, Query Dissemination Cost, WWW 2007