Study On The Vector Spatial Data Index Models And Searching Algorithms For Peer-to-Peer Environments

Spatial data management software applications have important roles in software development. Peer-to-peer computing environment can give full play to participating nodes of the computer network and it can effectively use the capacity of network bandwidth. It provides a new optional architecture for spatial data sharing and management. It is necessary to establish a highly efficient distributed spatial data indexing for the management of complex spatial data in the peer-to-peer environment. Higher applications can use the index to determine how the spatial data stored in peer-to-peer environment, be able to quickly find the required spatial data, be able to use spatial data to facilitate the provision of related services.Index design goal is to support users to access massive vector spatial data and to eliminate the performance bottlenecks of client / server architecture. The model should be able to support the peer frequent entry / exit system, be able to adaptively adjust well. The model should be able to support spatial data associated property management. Users of system can be able to query the property of spatial data.The P2PQR-tree is the spatial data index model designed in P2P environment. P2PQR-tree model uses structured overlay network as a network routing and location layer, which simplified the design of distributed spatial data index and reused the mature theory and technology of structured overlay network. P2PQR-tree puts MX-CIF quadtree extended to a distributed environment, and uses the replication strategy to achieve load balancing effect. P2PQR-tree uses spatial data collection to organize spatial data, designs a two-tier index.A variety of algorithms are designed and analysis on the basis of P2PQR-tree, which include index generate and maintain algorithms and distributed range query algorithm and distributed nearest neighbor query algorithm and so on. Distributed property query algorithm is designed to test the relationship of property and spatial data. Through theoretical analysis, these algorithms have good performance in peer-to-peer computing environment, and already meet the requirements of the design goals.Map library is an important method to organize the massive spatial data in practice. This paper studies the model of map library management in peer-to-peer environments. The architecture of P2P map library model is designed on the basis of the concept of map library. P2P map library is also based on structured overlay network based on the use of library metadata, design a more simple and efficient distributed indexing program. This paper designs the index init and maintenance algorithms, distributed spatial range queries and distributed query property query algorithms For P2P map library model, and does the theoretical analysis of algorithms.Through theoretical analysis and prototype experimental analysis, P2PQR-tree model, P2P map library model and the relevant algorithms remission the bottleneck of client / server architecture, the use of the system's ability to each node to achieve load balancing.There are some improvements compared with distributed quadtree.P2PQR-tree uses the spatial data collection to organize data, which can makes a more structured organization of data and can be from a professional point of data classification, access control, the structure of property management, meta-data description. The use of the local index can take some advantages. Entities to add, delete, change, etc. only need to update the local index, the index of distributed basic no impact. The local data modification Implements the decentralized data maintenance, so that large-scale data maintenance more feasible.In P2P environment, peers frequent entry/quit to the network, P2PQR-tree index only necessary synchronization FC data, spatial data itself remains stable, so as to reduce the network load.P2PQR-tree uses a replication strategy so that the distributed quadtree maintained the original MX-CIF quadtree characteristics simultaneously achieved the load balancing.P2P map library model has been designed based on P2PQR-tree and optimized for map library. The range query and attributes query reduce messages num through nodes...