A partial implementation of a relational data-base management system as an extension to FORTRAN

In general applications of a Data Base Management System (DBMS) for centralised monitoring of a medium sized data base, a Relational approach is often said to be preferred to a Hierarchical or a Network approach, because of its simplicity and ease of usage. An experimental Relational DBMS has been implemented at the Computer Centre of the Indian Institute of Technology, Kanpur, India. This system provides most of the facilities required for a Data Model Definition, Data Sub-language, and Data Manipulation Language. The FORTRAN language was selected as the host, because of its popularity and the available system software. The resulting DBMS has been tested on live data and the results have been encouraging.     

The need for a DML: Why a library interface isn''t enough

‘Associative Access’ will contribute significant benefits to object-oriented data base management systems and is best obtained through embedded Data Manipulation Languages. This conclusion stresses the need for a standard DML.     

一个适合复杂对象管理的层次—关系模型

本文提出了管理复杂对象实用而经济的数据模型－“层次－关系“模型。ＯＯＤＢ方法无疑是处理复杂对象有效的方法，然而实现一个纯粹的ＯＯＤＢＭＳ其工作量和复杂度都难以在近期使用它。语义联系模型在表达客观事物的语义联系上有其独特的功能，而描述复杂对象的内部结构则显得力不从心。基于传统数据模型组合和扩充的“层次－关系“模型，吸取ＯＯＤＢ静态结构继承的思想，利用了层闪模型和关系模型已有的技术和其优点，是处理复杂     

浅析SQL Server2005中的DDL触发器技术

SQL Server2005扩展了触发器的功能,从数据操纵语言又增加了数据定义语言,这项新技术叫DDL触发器。分析了DDL触发器的基本功能、工作原理及用法,举例说明了DDL的两种基本应用。     

A survey of distributed data base management

A survey of the literature on Distributed Data Base Management Systems is presented. The problems associated with distributing data throughout a network are summarized into two major areas: Data Distribution and Data Transfer. Each area is described detailing some of the major proposed solutions to the problems therein. The intention here is to provide the reader with an overview and an extensive bibliography for further study on any aspect of Distributed DBMS.     

一种基于框架和中间件模型的知识库系统

本文基于对知识库系统的分析、在现有的数据库管理系统上提出了一套规则、知识框架,并围绕框架构造一个专家系统中间件,以实现规则、知识库与数据库的结合,这套方案立足于利用常规开发工具（如：VB、VC、PB等）在数据库管理系统（如：Oracal、SQL、Server等）上开发集成专家系统的复杂MIS。     

化工工艺CAD数据库设计

本文对化工工艺辅助设计中的数据库及其管理系统的功能，构成和发展趋势作了较为全面的论述，并在此基础上提出化工工艺ＣＡＤ数据库及其管理系统的设计原则，方法，同时开发了此数据库及其管理系统。     

应用BLP模型对PostgreSQL进行安全增强

文章讨论了应用BLP模型公开源码数据库PostgreSQL进行安全增强、实现安全数据库原型系统的原理与技术细节。文中概括介绍了BLP模型原理及PostgreSQL软件结构,详细阐述了原型系统安全标识实现、PostgreSQL系统原有数据字典的改造、DDL和DML语言的改造,并介绍了多级关系的分解与恢复算法。     

DML触发器实现数据完整性的应用研究

数据完整性是确保数据库数据安全的重要研究内容。通过DML触发器技术实现数据完整性控制,可有效防止由于对数据进行频繁的更新操作从而导致数据丢失或无效扩散。该文通过论述DML触发器的实现机制,并结合具体的开发实例,分析DML触发器在强制数据参照完整性、级联更新与删除、实现用户定义业务规则、更新不可更新视图等方面的应用基本步骤及设计技巧,反映了触发器应用在提高系统性能、简化数据库操作、维护数据完整性、有效性、增强数据库安全性、提高开发效率等方面的强大功能。     

Query triggers for XML DBMS: Efficient implementation based on shadow mechanism

Active database systems extend functionality of traditional database systems with powerful mechanisms of triggers (or active rules) support. Triggers provide a uniform and convenient base that can be used for realization of internal DBMS functions, such as support of integrity constraints, representations, access authorization, statistics gathering, monitoring and notifications and for higher efficiency of external applications. Among representative examples of external applications that can be based on the usage of properties of active DBMS are data-intensive expert systems and workflow management systems. Today, the majority of industrial relational DBMS already support triggers, while XML DBMS, which are comparatively new, lack such functionality. Expansion of the XML DBMS application field and its usage in constructing complex application system stimulates appearance of new research works aimed at extending the functionality of XML DBMS by trigger support.In this paper, the authors define a special type of triggers for XML DBMS—XML triggers responding to data retrieval—and propose methods for their implementation. The paper also discusses examples of applications where XML query triggers occur to be useful and gives review of existing research works in this area.     

重建数据立方体的数据覆盖方法

数据切片体现了数据立方体某方面的数据特征,当产生数据切片的数据立方体由于某种原因不可访问时,通过已知的多个数据切片尽可能地恢复数据立方体中的原始信息,有利于对数据的深入分析和理解.提出了一种基于数据切片重建数据立方体的方法,通过数据切片的连接生成多维细粒度空间,利用数据覆盖操作逐步细分每个数据切片所对应的多维空间,以逼近多维细粒度空间.提出了重建后数据立方体的可查询判据.该方法直接利用数据库中的基本操作来实现,高效地支持大数据量的应用环境.     

Systems Dynamics-Based Modeling of Data Warehouse Quality

ABSTRACT

Data warehouses (DW) are a key component of business intelligence and decision-making. In this paper, we present an approach that combines Grounded Theory and System Dynamics to develop causal loop diagrams/models for data warehouse quality and processes. We used the top 51 data warehousing academic papers to arrive at concepts and critical success factors. A simple data warehouse quality causal model and a Data Warehouse Project Initialization Loop Analysis, Data Source Availability & Monitoring Loop Analysis and Data Model Quality and DBMS Quality Analysis models were developed. Visualization of the cause-effect loops and how data warehouse variables are interrelated provide a clear understanding of DW process. Key findings include data quality and data model quality that are more important than DBMS quality for ensuring data warehouse quality, and the number of data entry errors and the level of data complexity can be major detriments to DW quality.     

基于PostgreSQL的强制访问控制的实现

讨论一个基于公开源码数据库PostgreSQL的安全数据库原型系统中强制访问控制机制的现,详细阐述了原型系统对PostgreSQL系统原有数据字典的更改及时DDL、DMI。语言的改造,并介绍了多缀关系的分解与恢复算法。     

Quantitative evaluation of micro versus larger database products

This paper uses a model of the functional structure of database management systems (DBMS) and quantitative methods for evaluation in order to compare functional capabilities of the micro DBMS products with those of the larger ones. To this end, two micro products, dBASE III (version 1.1) and R:Base 5000 (version 1.0) and a larger product: VAX-11 Datatrieve are compared. The results show only marginal distinction between micro and larger DBMS products on the basis of functional capabilities — a distinction which is likely to disappear in the near future.     

A compiler model for a relational data base management system

One of the chief difficulties which needs to be overcome during the early design stages of a system is that of establishing a satisfactory design for that system. From the time it was first conceived it was apparent that the Relational Data Base Management System is like a compiler in so far as it takes a succession of user requests for information formulated in an applied predicate calculus and translates each one into a series of calls which access an underlying data base and transform data from that data base into the form the user wishes to see. This paper compares the architecture of the Relational Data Base Management System with that of a compiler, and then demonstrates the use of the architecture when processing a language based on an applied predicate calculus. Finally, the paper describes a number of extensions to that architecture which are required to solve the particular problems raised by the data base system.     

关于数据库技术研究及发展现状的探讨

数据库技术是现代信息系统的重要技术基础。在分析数据库技术的研究和发展现状后 ,介绍了当前流行的几种数据库技术 ,如面向对象数据库、分布式数据库、数据仓库、数据挖掘、Web数据库等等 ,同时指出其应用领域和发展趋势     

Pauses in doctor–patient conversation during computer use: The design significance of their durations and accompanying topic changes

Talk is often suspended during medical consultations while the clinician interacts with the patient's records and other information. This study of four general practitioners (GPs) focused on these suspensions and the adjacent conversational turns. Conversation analysis revealed how GPs took action to close conversations down prior to attending to the records, resulting in a ‘free turn’ that could be taken up by either GP or patient. The durations of the intervening pauses were also analysed, exposing a hitherto unobserved 10-second timeframe within which both GP and patient showed a preference for the conversation to be resumed. Resumption was more likely to be achieved within 10 s when the GP's records were paper-based rather than computer-based. Subsequent analysis of topic changes on resumption of talk has revealed a 5-second timeframe, also undocumented; when pauses exceed this timeframe, it is rare for the previous topic to be resumed without a restatement. Data recorded in the home suggest that these timeframes are also present in family conversations. We argue for considering the two timeframes when designing systems for use in medical consultations and other conversational settings, and discuss possible outcomes.     

基于空间数据引擎的企业化GIS数据组织与处理

空间数据引擎是近年来发展起来的采用大型ＲＤＢＭＳ管理空间数据的新技术,它为ＧＩＳ海量数据的组织与共享提供了极大的方便。该文从ＧＩＳ现状和空间数据引擎的原理及相关技术与标准出发,提出基于空间数据引率的企业化ＧＩＳ的构建模式和构建步骤,指出了用空间数据引擎建立企业化ＧＩＳ的优点和不足,并借鉴ＩｎｔｅｒｎｅｔＧＩＳ中的数据获取部件来弥补它互操作的不足,最后对当今与空间数据引擎有关的ＧＩＳ发展的新问题进行     

并行数据仓库Para Ware系统的查询优化

1.引言数据仓库作为支持OLAP应用的系统,它所面对的数据往往都具有很大的规模。如何快速地得到查询结果,一直是人们研究的一个重要方向。在已有的研究中,已经相继提出了使用实体化视图和各种有效的索引技术来提高查询响应性能。使用实体化视图是通过数据的冗余存储,对于常用的聚集数据进行预计算,使用预计算结果响应用户查询。而索引技术也主要是应用在存储层上的,如在文[4]中提到在存储层中使用bitmap索引提取相关数据的方法。而在查询处理逻辑层次上的优化技术目前研究得还比较少。在文[3]中提到了使用缓存技术,减少磁盘I/O及通信代价,提高查询效率的方法,这个