【摘要】 在数据仓库中存在着大量的数据。联机分析处理包含着对大量数据的复杂的查询过程。在对这些数据的存储与查询中都遇到了许多困难。解决这一问题的有效办法就是先将数据划分成便于处理的数据块 ,再分别对每个数据块进行处理 ,最后将各个数据块的处理结果归并在一起。对几种常用的归并算法进行了比较 ,并讨论了归并中的缓冲区分配问题更多还原

【Abstract】 Data warehouses contain large amounts of information and on-line analytical processing(OLAP), involve hundreds of complex aggregate queries over large volumes of data. In the process of storing and querying on these data, we are faced with many difficulties. One effective access to solve this problem is to partition these data into data blocks, which are easy to process and process these data blocks individually. Then merge the results together. In this paper, We compared several typical merging algorithms, and discussed the assignment of data buffer in the process of merging.更多还原