对基于R-Tree的空间连接代价模型进行了探讨,主要研究了HUANG Y W提出的空间连接代价模型。利用最优/最差选择策略降低该算法的时间复杂度,对基于缓冲区的代价模型提出了改进后的评估公式,通过实验验证了改进后的模型比原模型提高了评...对基于R-Tree的空间连接代价模型进行了探讨,主要研究了HUANG Y W提出的空间连接代价模型。利用最优/最差选择策略降低该算法的时间复杂度,对基于缓冲区的代价模型提出了改进后的评估公式,通过实验验证了改进后的模型比原模型提高了评估的精确度。展开更多
This paper proposes a fast initial construction method of the GBD-tree. The GDB tree has proper characteristics for management of large amount of 2 or 3 dimensional data. However, the GBD-tree needs long initial const...This paper proposes a fast initial construction method of the GBD-tree. The GDB tree has proper characteristics for management of large amount of 2 or 3 dimensional data. However, the GBD-tree needs long initial construction time by originally proposed one-by-one insertion method. A fast insertion method has been proposed, but it needs large size of buffer capable to hold index information of all entries. The paper proposes another fast initial construction method. The method requires only limited size of work space (buffer). The experimental results show the initial construction time reduces into a third or a quarter of the one-by-one insertion method. The memory efficiency and retrieval efficiency are also improved than the one-by-one insertion method.展开更多
文摘This paper proposes a fast initial construction method of the GBD-tree. The GDB tree has proper characteristics for management of large amount of 2 or 3 dimensional data. However, the GBD-tree needs long initial construction time by originally proposed one-by-one insertion method. A fast insertion method has been proposed, but it needs large size of buffer capable to hold index information of all entries. The paper proposes another fast initial construction method. The method requires only limited size of work space (buffer). The experimental results show the initial construction time reduces into a third or a quarter of the one-by-one insertion method. The memory efficiency and retrieval efficiency are also improved than the one-by-one insertion method.
