OceanBase中基于布隆过滤器的连接算法

A join algorithm based on bloom filter in OceanBase

在大数据时代,"去IOE"运动的推进以及"双11"等活动的兴起对分布式数据库系统提出了更高的要求.OceanBase是阿里巴巴集团自主研发的开源分布式数据库,支持海量数据跨行跨表事务,但是对复杂查询的处理性能仍有待提高,其中连接操作带来的网络传输严重影响了数据库的性能.本文提出了一种基于布隆过滤器的连接算法,通过构建布隆过滤器对右表数据进行过滤,减少了不必要的数据传输开销,降低了数据处理带来的内存资源的消耗.本文在OceanBase上实现了该算法,并通过实验证明,该算法极大提高了连接操作的效率.

In the era of big data, the movement of ＂de-IOE＂ campaign and the development of activities such as Double 11 have put forward higher request of the performance of distributed database. OceanBase is an open sourced distributed database implemented by Alibaba. It supports for cross-table relational query of massive data but the performance for complex queries remains to be improved. The network transmission overheads caused by join operator seriously influenced the performance of distributed database. This paper proposes a join algorithm based on bloom filter. It filters the data of the right table by constructing a bloom filter on the join column of the left table. The key point of this algorithm is that it reduces the overhead of unnecessary data transmission and the consumption of memory resources by data processing. We implement this algorithm in OceanBase and the experiment results show that the algorithm can greatly improve the efficiency of join operator.