【作者】 吴涵；

【导师】 杨克俭；

【作者基本信息】 武汉理工大学 ， 计算机应用技术， 2008， 硕士

【摘要】 数据库技术是信息系统的核心和基础,它的出现极大的促进了计算机应用向各行各业的渗透。数据库技术的出现正是为了满足人们对管理庞大的信息资源并加以有效的利用的需求。对于仿真系统而言,如何对海量仿真数据进行有效的存储和读取是仿真系统中一个重要的方面,它直接影响到仿真系统的性能和应用面。目前的一些商业数据库虽然实现的功能很强大,但是往往与系统平台结合比较紧密,并且封装也比较麻烦,这就限制了仿真系统的应用面。因此,为了满足仿真平台的应用需求,开发出一套与平台无关的数据库引擎具有很重要的意义。本文根据仿真系统的应用需求来设计数据库系统,最主要的是实现跨平台和运行时的系统开销,使得数据库系统在任何平台下都能够运行。基于这个思想的指导下,设计并实现了一个通用的可以运行于不同操作系统平台的基于文件系统的小型数据库系统。本文的主要工作包括对数据库系统特点及发展趋势进行分析,并完成了数据库管理系统的体系结构设计及数据的组织结构设计,对数据库系统的索引结构进行了讨论和研究,在文件的格式设计上则采用UTF-8的形式来编码。本文从编译原理入手,在研究编译过程及相关知识的基础上,研究了数据库查询语言SQL从底层数据结构到上层语法分析的实现过程。在对SQL语言解释时使用LEX和Lemon工具软件。在虚拟机的解释器模块设计中借鉴了Java虚拟机的思想,使用栈式的设计方法简单并快速地实现解释器,并对虚拟机实现的关键技术进行了探讨和研究,并分析了虚拟机执行SQL语言的步骤。本文针对用户对查询效率要求较高的特点,引进了SQL预处理器,对预处理器的功能进行了描述,同时也对容易出现的SQL语句错误进行了定义,以及对SQL语言实现的几个重要方面做了论述。本文在数据安全性和共享方面引进了锁机制来保证事务的可串行性调度。采用Socket实现了简单的网络通信,同时对用户的标识与鉴别进行了探讨。更多还原

【Abstract】 Database technology is the core and base of the information system and it greatly advances the penetration of computer technology into other disciplines.The presence of database technology intends to satisfy the people’s needs to manage the abundant information resources and to make good use of them.In regards to simulation system,how to store and read the simulation data effectively is of great significance due to the huge volume of the data to be managed,and it can directly affect the performance and application of the simulation system.At present,there are meny Database have powerful function,But a Database more closely integrated with the platform and the encapsulation is comparatively inconvenient,which limits the application range of simulation systems.Therefore,the development of a micro-database engine to meet specific applications of simulation platform becomes significative.This paper designs database system according to the requirement of the application of the simulation system,and ensure its cross-platform operation.A platform independent,file system based minitype database system was implemented based on this idea.The main job of this article includes the analysis of the characteristics and developmental tendency,the design of the distributed and organized structure,the specified discussion and exploration of the structure index,and on the format design of the document using UTF-8 to code.This article is based on the Principle of compiler.After considered the process and theories of the complier,the article realized a basic structure used in DBMS and a SQL syntax analyzer as well,and explain the SQL language using software of the LEX and the Lemon.The thought of Java virtual machine has profited in the virtual machine interpreter Module design.The stack design method can help to implement the interpretor fast and easily,and the key technique in implementing the virtual machine is discussed and explored,and analyzed the step of the performance of SQL language with virtual Machine.This article aims at the request of the customer to have search with a higher efficiency,so indraught a preprocessor of SQL,carrying on a description to the function of the preprocessor,and the common mistakes of the SQL sentences were defined.Meanwhile,the key aspects of implementing the SQL language were discussed.For security and share of the data,the lock scheme technique was employed to ensure the serializability of the events.Socket technology was used to achieve simple network communication.The identification and discrimination of the user was also discussed.更多还原