一种磁盘历史数据库模型研究

Research on a Disk History Database Model

为解决流程工业中过程历史数据的存储以及大量数据的快速查询问题,提出一种基于关系数据库的磁盘历史数据库模型。在数据存储方案设计中,将关于位号和数据采集接口的静态信息存储在关系数据库中,历史数据以文件形式存放,采用三重二级缓存机制避免频繁访问磁盘,并使用经典的SDT算法对实时数据进行压缩存储,降低存储成本。数据查询方案采用三级索引文件结构,即总索引文件、二级索引文件和位号索引文件,提高查询效率。该磁盘历史数据库的第一版已经成功实现,应用结果表明,数据存储方案和查询方案的设计是合理的,100个位号的查询时间约为500 ms。

In order to solve the problem of storing process history data and fastly querying large amounts, this paper proposes a disk history database model based on relational database. In the storage design, static information about the tags and data collect interfaces are stored in relational database. History data is stored in files, and a mechanism named triple secondary cache is used in RAM, thus the frequency of disk access is reduced. Meanwhile, the SDT algorithm is also used in data processing to reduce storage cost. In order to improve the efficiency of query, three-level index file structure which consists of a total index file, secondary index file and tag number index file is adopted in the data query scheme. The first version of the model is implemented. Applications result shows that the storage and query scheme is reasonable, and it returns the results of 100 tag numbers in about 500 ms.