Volume : III, Issue : V, May - 2013

Query Planning of Continuous Aggregation Queries Over Network

Prof. Y. B. Gurav, Mrs. Manjiri Deshmukh

Abstract :

To monitor the time varying data we required some queries and those queries are continuous queries which provides result for online decision making Typically a user desires to obtain the value of some aggregation function over distributed data items, for example, to know value of portfolio for a client; or the AVG of temperatures sensed by a set of sensors. In these queries a client specifies a coherency requirement as part of the query. This paper presents a low–cost, scalable technique to answer continuous aggregation queries using a network of aggregators 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 (CDN) 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. Provide a technique for getting the optimal set of subqueries with their incoherency bounds which satisfies client querys coherency requirement with least number of refresh messages sent from aggregators to the client. For estimating the number of refresh messages, Build a query cost model which can be used to estimate the number of messages required to satisfy the client specified incoherency bound.

Keywords :

Article: Download PDF   DOI : 10.36106/ijar  

Cite This Article:

Prof. Y. B. Gurav, Mrs. Manjiri Deshmukh Query Planning of Continuous Aggregation Queries Over Network Indian Journal of Applied Research, Vol.III, Issue.V May 2013

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