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关键词： 嵌入式数据库系统   安全机制   影响因素   身份认证机制  

摘要： 本文针对嵌入式数据库系统安全问题展开研究,笔者通过分析各项对嵌入式数据库系统安全产生影响的因素,归纳用户对于嵌入式数据库系统安全的各项需求。基于此,提出嵌入式数据库系统各种安全机制的设计及实现方法,主要包含安全通信机制、身份认证机制设计等,以确保嵌入式数据库系统的安全。研究结果表明,所设计的嵌入式数据库系统各种安全机制满足用户对系统的实际需求,实现数据库系统各客户端和服务器安全连接及合理控制数据访问,保障数据通信安全。

关键词： 海量信息   数据库   系统安全  

摘要： 通过授权访问、内外网隔离、IP管理、软件设计等方式,加强对网络信息空间的控制能力,保证系统的稳定性和安全性,实现海量信息数据库信息系统的安全管理。

关键词： SQLite   TPC—E   基准测试   数据库系统  

摘要： TPC-E是TPC(transaction processing performance council,事务处理性能委员会)组织发布的新一代数据库性能评测标准,用于取代日渐老化的TPC-C标准。SQLite是目前被广泛使用的一种嵌入式数据库,研究在TPC-E标准下的SQLite具体性能表现对实际应用具有重要参考意义。然而,目前业界缺少面向SQLite的TPC-E实现。为了解决该问题,设计和实现了面向嵌入式轻量级数据库SQLite的TPC-E基准测试系统,它不仅可以为SQLite数据库提供准确高效的性能评测系统,而且对SQLite在市场上的扩展应用和开发具有重要的参考价值。该测试系统严格遵循TPC组织最新发布的OLTP性能评测基准TPC-E,不仅能对SQLite作为内存数据库与文件数据库时的数据库特性进行精确有效的性能评测,还能客观真实地获得SQLite数据库的性能评测数据。实验结果表明,在TPC-E负载下,与Oracle等重量级的关系型数据库相比,SQLite事务处理性能较低。但由于其简单易用和体积小等优势,SQLite在实时性高的行业小型智能设备方面的应用依然具有较大的优势。同时通过对实验结果的分析,指出了制约SQLite性能的主要原因。

摘要： Several contributions that would help readers to enhance their knowledge in database systems, game engineering, and data mining are introduced. Over the course of the last twenty years, research in data mining and databases have seen a substantial increase in interest, attracting original contributions from various disciplines including computer science, electrical engineering, games engineering systems, genetics engineering, statistics, operations research, and information systems. In Mardini et al address the issue of link selection of friends and analyzes five strategies in the literatim. Then it proposes a link selection strategy using the Genetic Algorithm (GA) to find the near optimal solution. The results show an improvement over the examined strategies in terms of several parameters.

关键词： esophageal surgery   evidence-based medicine   surgery   gastric surgery   surgical oncology  

摘要： Background. The term big data refers to databases that include large amounts of information used in various areas of knowledge. Currently, there are large databases that allow the evaluation of postoperative evolution, such as the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP), the Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS), and the National Cancer Database (NCDB). The aim of this review was to evaluate the clinical impact of information obtained from these registries regarding gastroesophageal surgery. Methods. A systematic review using the Meta-analysis of Observational Studies in Epidemiology guidelines was performed. The research was carried out using the PubMed database identifying 251 articles. All outcomes related to gastroesophageal surgery were analyzed. Results. A total of 34 articles published between January 2007 and July 2017 were included, for a total of 345 697 patients. Studies were analyzed and divided according to the type of surgery and main theme in (1) esophageal surgery and (2) gastric surgery. Conclusions. The information provided by these databases is an effective way to obtain levels of evidence not obtainable by conventional methods. Furthermore, this information is useful for the external validation of previous studies, to establish benchmarks that allow comparisons between centers and have a positive impact on the quality of care.

关键词： SQL语言  

ISBN: (纸本)9787115483065

摘要： 本书主要内容包括：1绪论、2关系型数据库和非关系型数据库的原理对比、3 Hbase基本原理、4Hbase的维护管理和深化应用、5环形的Key-value数据库基本原理、6文档型数据库基本原理、7其它非关系型数据库简介、8课程展望。

关键词： Vxworks   数据库   海事记录仪   实时性  

摘要： 现代船舶运输在全球经济中扮演着重要角色,因而对船舶制造以及相关自动化技术的要求也越来越高。海事记录仪能够对船舶航行数据进行实时记录,可以作为改进船舶设计的参考和船舶事故的证据。本文提出了一种基于Vxworks实时数据库系统的海事记录仪,对Vxworks实时数据库系统进行了简要介绍和分析,在此基础上阐述了海事记录仪的功能,并设计了系统结构,最后对Vxworks实时数据库系统的实现进行了详细阐述。同传统的数据库系统相比,本系统具有良好的实时性。

关键词： 数据库   振动环境  

摘要： 全机振动环境数据是民用飞机机载设备设计、验证的基本输入,对民机研制具有十分重要的意义。本文根据目前飞机研制进度需求,通过梳理民机振动环境试飞数据的特点,结合常规数据库设计思路,给出了民机振动环境试飞数据库的需求分析、概念设计和逻辑结构设计,并提出了硬件系统性能要求。

关键词： ORM   数据整合   海洋信息   综合数据库  

摘要： 为了适应信息技术的发展,打破海洋多个系统间数据隔离造成的"数据烟囱"、"数据孤岛"现状,本文提出一种改进的自适应ORM框架,并基于此框架建设一套切实可行的海洋综合数据库管理系统,将涉及海洋领域的所有数据汇集到海洋综合数据库,实现数据的统一管理、统一维护;并通过建立合理的数据调取机制,为海洋信息化系统提供强有力的数据支撑,使其满足信息化应用需求。

关键词： Taxonomy   workload management   database management systems  

摘要： Workload management is the discipline of effectively monitoring, managing and controlling work flow across computing systems. In particular, workload management in database management systems (DBMSs) is the process or act of monitoring and controlling work (i.e., requests) executing on a database system in order to make efficient use of system resources in addition to achieving any performance objectives assigned to that work. In the past decade, workload management studies and practice have made considerable progress in both academia and industry. New techniques have been proposed by researchers, and new features of workload management facilities have been implemented in most commercial database products. In this paper, we provide a systematic study of workload management in today's DBMSs by developing a taxonomy of workload management techniques. We apply the taxonomy to evaluate and classify existing workload management techniques implemented in the commercial databases and available in the recent research literature. We also introduce the underlying principles of today's workload management technology for DBMSs, discuss open problems, and outline some research opportunities in this research area.