【摘要】 随着大数据应用日益增多,NoSQL(not only structured query language)数据库管理系统得到了快速发展。如何对NoSQL数据库和关系型数据库进行有效集成成为研究热点之一。在现有研究成果中,在这些异构的多数据库之间进行联接(join)操作时,所采用的分页查询方法产生的延迟较大。针对这一问题,提出了一种分页预取的模型,并重点研究了其基本构成、预取方式以及运行机制。基于该模型,设计开发了原型系统,对其效果进行了验证,达到了预期目标。与无预取的分页查询方法相比,所建模型可以减少分页查询延迟,从而提升跨数据库联接操作的效率。更多还原

【Abstract】 As the applications of big data are increasing, the NoSQL(Not only Structured Query Language) database management systems have been developed rapidly. How to integrate NoSQL database and relational database effectively has become one of the research hotspots. In the existing research results, the paged query method used for join operations of these heterogeneous multi-databases can produce a large delay. In view of this deficiency, this paper presents a paged prefetching model, and focuses on its basic composition, prefetching mode and operation mechanism. A prototype system is designed and developed. The effect of this model is verified, and the expected targets are achieved. Compared with the non-prefetched paging query method, the outstanding contribution of this research result is that it can reduce the delay of paging query and thus improve the efficiency of the join operations of cross-databases.更多还原