| 摘要: |
| 本文提出了一种新的动态Hash连接方法──DHJ（dynamichash join），以解决并行数据库连接操作中的数据偏斜现象.为避免目前某些算法提出的预处理中隐含的高额费用，该方法在划分阶段通过增添附加桶的方法来平衡输出，然后依据计算确认哪些附加桶被映射到处理器上并确定处理器分配，在最后阶段完成连接.本文最后给出了该算法的性能分析. |
| 关键词: 连接 数据偏斜 动态Hash 桶 平衡输出 |
| DOI： |
| 分类号: |
| 基金项目:本文得到国家自然科学基金资助. |
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| A DYNAMIC HASH JOIN ALGORITHM TO AVOID DATA SKEW |
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HONG Xiaoguang,WANG Xinjun,DONG Jirun
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| Abstract: |
| In this paper, a new hash join algorithm-DHJ(the dynamic hash join) is proposed to resolve the problem of skewed data in the join operation in parallel database.The objective of the algorithm is to avoid the high cost of processing inherent in some early work. Additional buckets are used in the algorithm to balance output during the data partition. Then they are mapped to different processors before the completion of the join operation. The performance analysis of the algorithm is provided in this paper. |
| Key words: Join data skew dynamic hash bucket balance output |
