Study on Clustering-Based Location Dependent Query

2012 ◽  
Vol 532-533 ◽  
pp. 897-901
Author(s):  
Ming Jun Wei ◽  
Li Chun Xia ◽  
Jian Guo Jin ◽  
Qiu Hong Fan
Keyword(s):  
Mobile Computing ◽  
Query Processing ◽  
Location Analysis ◽  
System Efficiency ◽  
Analysis Algorithm ◽  
System Resources ◽  
Location Dependent Query ◽  
Special Case ◽  
New Location

This paper firstly analyzes the importance and necessity of location dependent query in the mobile computing. Then, it proposes a special case in the application of the location dependent query. That is as follows: Inquirers may send the same location dependent query in different but similar positions. However, the server will not deal with them together but treat them separately. Thus, it will not only cause the waste of system resources but also delay disposal of other queries. According to the principal of clustering we propose a new location Analysis Algorithms-similar merging location analysis algorithm (SMLA). By the algorithm, similar queries can be combined into the same query, so as to reduce the load on central servers, improve system efficiency and query processing performance.

scholarly journals Location-Dependent Query Processing Under Soft Real-Time Constraints

2009 ◽  
Vol 5 (3) ◽  
pp. 205-232 ◽  
Author(s):  
Zoubir Mammeri ◽  
Franck Morvan ◽  
Abdelkader Hameurlain ◽  
Nadhem Marsit
Keyword(s):  
Performance Evaluation ◽  
Query Processing ◽  
Real Time ◽  
Mobile Devices ◽  
Communication Cost ◽  
Time Constraints ◽  
Mobile Clients ◽  
Location Dependent Query

In recent years, mobile devices and applications achieved an increasing development. In database field, this development required methods to consider new query types like location-dependent queries (i.e. the query results depend on the query issuer location). Although several researches addressed problems related to location-dependent query processing, a few works considered timing requirements that may be associated with queries (i.e., the query results must be delivered to mobile clients on time). The main objective of this paper is to propose a solution for location-dependent query processing under soft real-time constraints. Hence, we propose methods to take into account client location-dependency and to maximize the percentage of queries respecting their deadlines. We validate our proposal by implementing a prototype based on Oracle DBMS. Performance evaluation results show that the proposed solution optimizes the percentage of queries meeting their deadlines and the communication cost.

Partial Global Indexing for Location-Dependent Query Processing

2007 ◽  
pp. 739-743
Author(s):  
J. Jayaputera
Keyword(s):  
Simulation Model ◽  
Query Processing ◽  
Access Time ◽  
Current Cell ◽  
Local Storage ◽  
Location Dependent Query ◽  
Future Work

The idea of this article is based on the parallel indexing concept (Taniar & Rahayu, 2002) in which an indexed object residing in a BS is either fully, partially, or not replicated to others BSs. Therefore, every server contains either partial or all indexes of other servers. In our proposed approach, whenever the requested results return from neighboring cells, we append the resulting items to the current cell. This implies that when the next user sends a request, the current cell needs to look up its own index first to verify if the data is in its local storage. If the data is not present, the current server sends a request to the neighboring cells on behalf of the client; otherwise, the current server directly sends the requested query to the client. We have evaluated our proposed approach and showed that the access time can be reduced by a factor of two.The next section of this article describes some related work. We then describe our proposed work and the simulation model, and we compare the performance of our proposed technique to other techniques. Finally, we conclude the article and suggest future work.

scholarly journals Research in Mobile Database Query Optimization and Processing

2005 ◽  
Vol 1 (4) ◽  
pp. 225-252 ◽  
Author(s):  
Agustinus Borgy Waluyo ◽  
Bala Srinivasan ◽  
David Taniar
Keyword(s):  
Mobile Computing ◽  
Query Processing ◽  
Query Optimization ◽  
Management Strategy ◽  
Data Dissemination ◽  
Replacement Policy ◽  
Processing Strategy ◽  
Mobile Databases ◽  
Periodic Broadcast ◽  
On Demand

The emergence of mobile computing provides the ability to access information at any time and place. However, as mobile computing environments have inherent factors like power, storage, asymmetric communication cost, and bandwidth limitations, efficient query processing and minimum query response time are definitely of great interest. This survey groups a variety of query optimization and processing mechanisms in mobile databases into two main categories, namely: (i) query processing strategy, and (ii) caching management strategy. Query processing includes both pull and push operations (broadcast mechanisms). We further classify push operation into on-demand broadcast and periodic broadcast. Push operation (on-demand broadcast) relates to designing techniques that enable the server to accommodate multiple requests so that the request can be processed efficiently. Push operation (periodic broadcast) corresponds to data dissemination strategies. In this scheme, several techniques to improve the query performance by broadcasting data to a population of mobile users are described. A caching management strategy defines a number of methods for maintaining cached data items in clients' local storage. This strategy considers critical caching issues such as caching granularity, caching coherence strategy and caching replacement policy. Finally, this survey concludes with several open issues relating to mobile query optimization and processing strategy.

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