Title
In-Network Execution of External Join for Sensor Networks
Abstract
Recently there have been growing interests in the applications of wireless sensor networks such as traffic tracking, environmental surveillance, and network monitoring. In these applications, the exploration of the relationship and linkage of sensing data with other data sources can be naturally expressed by the external join, where the sensory tuples join with an external table at the base station. However, executing such kind of join queries in a highly distributed and resource-constraint sensor network is a challenging task. In this paper, we propose a partition-based algorithm called NEJA (in-Network External Join Algorithm) for the external join processing in sensor networks. NEJA organizes the sensory data of the network through an optimized "value-to-storage" mapping, according to which each storage point stores the tuples that belong to the same subrange on the joint attribute. Then the subrange of each storage point is further partitioned into unit ranges, and tuples in the same unit range wisely choose their joining point that incurs the least communication cost based on a cost metric according to the latest historical statistics. Also, NEJA adopts some optimization techniques to handle the changes of sensory data and uses approximate approaches to cut down the maintenance cost of the mechanism. The experimental results indicate that our scheme is effective in reducing the amount of transmissions for the real time external join processing, especially when the external table has a relatively large size.
Year
DOI
Venue
2008
10.1109/WAIM.2008.43
WAIM
Keywords
Field
DocType
resource-constraint sensor network,storage point,maintenance cost,network monitoring,sensory tuples,sensor network,data source,sensor networks,unit range,sensory data,external join,in-network execution,external table,wireless sensor networks,wireless sensor network,base station,base stations,energy efficiency,real time,statistics,network externality,couplings,sensors,distributed databases
Hash join,Data mining,Base station,Recursive join,Tuple,Computer science,Sort-merge join,Network monitoring,Distributed database,Wireless sensor network,Distributed computing
Conference
Citations 
PageRank 
References 
2
0.37
17
Authors
3
Name
Order
Citations
PageRank
yongxuan lai111220.24
Yilong Chen2223.10
Hong Chen39923.20