spatial index impacts upon the efficiency of spatial query seriously in distributed spatial database. In this paper, we introduce a parallel spatial range query algorithm, based on VoMR-tree index, which incorporates ...
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spatial index impacts upon the efficiency of spatial query seriously in distributed spatial database. In this paper, we introduce a parallel spatial range query algorithm, based on VoMR-tree index, which incorporates Voronoi diagrams into MR-tree, benefiting from the nearest neighbors. We first augments MR-tree to store the nearest neighbors and constructs the VoMR-tree index by Voronoi diagram. We then propose a novel range query algorithm based on VoMR-tree index. In processing a range query, we discuss the data partition method so that we can improve the efficiency by parallelization in distributeddatabase. Just then a verification strategy is promoted. We show the superiority of the proposed method by extensive experiments using data sets of various sizes. The experimental results reveal that the proposed method improves the performance of range query processing up to three times in comparison with the widely-used R-tree variants.
Context management systems collect large volumes of spatial and non-spatial information. In particular, when these systems cover large areas like cities, countries or even the entire planet, the design of scalable sto...
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ISBN:
(纸本)9781424416622
Context management systems collect large volumes of spatial and non-spatial information. In particular, when these systems cover large areas like cities, countries or even the entire planet, the design of scalable storage, retrieval and delivery mechanisms is paramount. The Daidalos context management system has been design to meet the requirements of large scale systems. This paper presents the Daidalos approach for a scalable distributed data management approach. The system architecture, the management of mobile database nodes and federation issues are described.
Based on discussion on general methods of constructing global directory in DSMDS (distributed spatial database Management System), a new approach based on relation model was brought forward. It specifies three main co...
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ISBN:
(纸本)9780819465276
Based on discussion on general methods of constructing global directory in DSMDS (distributed spatial database Management System), a new approach based on relation model was brought forward. It specifies three main components of the global directory, including directory organization, directory update and extern interface. Then the authors implemented an actual global directory named SDirectoryService as well, key approaches and techniques in implementation were discussed in detail. Some experiments were designed and performed to check the efficiency, correctness and feasibility of the global directory, which reveal the directory works well on each aspect. By using the directory effective global query processing was achieved in DSMDS.
The balance of data and the utilization of resources are essential to distributed spatial database system. The paper presents an efficient parallel spatial query algorithm which takes seriously the organization of spa...
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ISBN:
(纸本)9781424420957
The balance of data and the utilization of resources are essential to distributed spatial database system. The paper presents an efficient parallel spatial query algorithm which takes seriously the organization of spatial data into account. The algorithm adopts a balanced spatial data partitioning strategy for distributed spatial databases. According to the characteristics of data partitioning, it builds a packing R-tree as its index. The strategy also considers the problem of computing distribution. By replicating index to every site, each site can access different entry in the same index node at the same time. Based on the organization of spatial data, the algorithm can simultaneously execute query operation at different site in both filtration phase and refinery phase. So it obviously improves spatial query performances. In order to solve multiple paths search problem caused by R-tree index, the algorithm brings in globe stack to buffer temporary index nodes. It settles the difficult problem flexibly in distributed spatial databases. For simplicity, the paper discusses the parallel algorithm in 2-dimensional space. Through the experiments conducting on many real datasets, it shows better performance in various spatial query operations.
The balance of data and the utilization of resources are essential to distributed spatial database system. The paper presents an efficient parallel spatial query algorithm which takes seriously the organization of spa...
详细信息
The balance of data and the utilization of resources are essential to distributed spatial database system. The paper presents an efficient parallel spatial query algorithm which takes seriously the organization of spatial data into account. The algorithm adopts a balanced spatial data partitioning strategy for distributed spatial databases. According to the characteristics of data partitioning, it builds a packing R-tree as its index. The strategy also considers the problem of computing distribution. By replicating index to every site, each site can access different entry in the same index node at the same time. Based on the organization of spatial data, the algorithm can simultaneously execute query operation at different site in both filtration phase and refinery phase. So it obviously improves spatial query performances. In order to solve multiple paths search problem caused by R-tree index, the algorithm brings in globe stack to buffer temporary index nodes. It settles the difficult problem flexibly in distributed spatial databases. For simplicity, the paper discusses the parallel algorithm in 2-dimensional space. Through the experiments conducting on many real datasets, it shows better performance in various spatial query operations.
spatial objects have two types of attributes: geometrical attributes and non-geometrical attributes, which belong to two different attribute domains (geometrical and non-geometrical domains). Although geometrically...
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spatial objects have two types of attributes: geometrical attributes and non-geometrical attributes, which belong to two different attribute domains (geometrical and non-geometrical domains). Although geometrically scattered in a geometrical domain, spatial objects may be similar to each other in a non-geometrical domain. Most existing clustering algorithms group spatial datasets into different compact regions in a geometrical domain without considering the aspect of a non-geometrical domain. However, many application scenarios require clustering results in which a cluster has not only high proximity in a geometrical domain, but also high similarity in a non-geometrical domain. This means constraints are imposed on the clustering goal from both geometrical and non-geometrical domains simultaneously. Such a clustering problem is called dual clustering. As distributed clustering applications become more and more popular, it is necessary to tackle the dual clustering problem in distributeddatabases. The DCAD algorithm is proposed to solve this problem. DCAD consists of two levels of clustering: local clustering and global clustering. First, clustering is conducted at each local site with a local clustering algorithm, and the features of local clusters are extracted clustering is obtained based on those features fective and efficient. Second, local features from each site are sent to a central site where global Experiments on both artificial and real spatial datasets show that DCAD is effective and efficient.
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