Embedding deductive capabilities in relational database systems

The basic idea of our work is to include deductive capabilities in a relational database system by fully using the operands of relational algebra and without using any theorem prover. We present a deductive database system where the user can formulate deduction laws as logical formulas, but which works on an underlying relational database system by fully using the data manipulation routines of such a system. Generally, it is not possible to express the deduction laws by means of expressions of relational algebra (see Ref. 1). In our system, a relational algebra expression is associated with every database deduction law. The result of its evaluation (with respect to an underlying database) is the set of all database entries that can be deduced from the database by applying the respective law once (Theorem 1). By successively applying all these relational expressions for all the database deduction laws it is possible to generate the whole extensional database (i.e. all tuples deducible from the database).     

一个演绎对象数据库SD-DOOD的设计与实现

通过探寻面向对象数据库与知识库技术相结合的途径,研究演绎对象数据库系统实现的关键技术。以基于演绎数据库系统SD-DDBS,设计实现了一个演绎对象数据库系统原型SD-DOOD。系统支持类、类层次、对象、属性、方法、继承和封装等面向对象数据库系统的核心概念,支持演绎对象等演绎数据库的概念,提供了图形用户接口(GUI),便于用户进行创建、查询等操作。     

The CORAL deductive system

CORAL is a deductive system that supports a rich declarative language, and an interface to C++, which allows for a combination of declarative and imperative programming. A CORAL declarative program can be organized as a collection of interacting modules. CORAL supports a wide range of evaluation strategies, and automatically chooses an efficient strategy for each module in the program. Users can guide query optimization by selecting from a wide range of control choices. The CORAL system provides imperative constructs to update, insert, and delete facts. Users can program in a combination of declarative CORAL and C++ extended with CORAL primitives. A high degree of extensibility is provided by allowing C++ programmers to use the class structure of C++ to enhance the CORAL implementation. CORAL provides support for main-memory data and, using the EXODUS storage manager, disk-resident data. We present a comprehensive view of the system from broad design goals, the language, and the architecture, to language interfaces and implementation details.Part of this article was presented at the International Conference on Very Large Databases, Vancouver, Canada, 1992; and at the ACM SIGMOD International Conference on the Management of Data, San Diego, California, 1993b.When the work was performed, Dr. Srivastava and Dr. Sudarshan were Research Assistants at the University of Wisconsin, Madison.     

演绎数据库中规则维护器的设计与实现

完整性维护是演绎数据库管理中的重要组成部分。首先给出演绎数据库系统的总体结构，然后重点介绍规则维护器的设计和实现，并阐述了规则操纵中完整性维护的基本算法。     

Knowledge-based system for supporting statistical database management

In the development of the expert system described here, knowledge-based information processing has been approached from the point of view of database technology. The outlines and processes of arranging an economic national balances system are provided, and the problems encountered in applying the variables involved in such a process to an expert system are identified. The structure and architecture of the expert system are defined, and the problems of knowledge acquisition are discussed.     

基于关系型数据库的公文工作流系统

根据公文流转的特点,对工作流模型进行了简化,并将这个简化模型建立在关系型数据库中。简化后的公文工作流模型呈树型结构,公文从树的枝节点向根节点流转、汇合,整个流转过程没有分支。讨论了公文工作流在关系型数据库中的数据存储结构,并以一个部级单位为例,给出了建立在这套模型之上的公文系统的实现方式。     

演绎对象数据库中基于行为规则的继承方法

在演绎对象数据库的研究和发展过程中,仍有两个重要的问题未能很好的解决：非单调的多值结构和行为规则的继承;基于规则的行为的封装。针对前一个问题,文中提出了几种解决的方法。特别是提出了一种新的继承方法——行为继承的回退,以获得更多的信息。通过一个数据库实例以及对它的查询,进一步说明这些继承的思想。     

ISIS Base化学数据库向关系数据库的迁移

ISIS Base是MDL公司提供的一个基于桌面的化学信息管理系统。利用ISIS Base用户可以对化学结构及相关的科学数据进行存储、搜寻和检索等管理工作。ISIS／Base基于表格的搜寻功能,可以让用户根据不同的需要将化学结构、文本及数字等类型的检索要求组合在一起,对相关的数据库进行检索和管理。但是它需要其它软件系统才能实现局域网和Internet应用。为了实现ISIS Base数据库中的数据在网络中的应用,本文介绍了一种ISIS Base数据向关系数据库迁移的方法。     

Managing the development of database systems

The technical problems of database systems, if not solved, are at least now understood, whereas the problems of implementation, evaluation and operation of these systems are less well appreciated even though they are being experienced by many organizations. A survey of some 200 organizations in the UK who are (or claim to be) database users highlights some of these problems and paves the way to more successful implementation strategies. The project and some of its findings are presented here.     

一种基于关系数据库的工作流管理系统的设计与实现

论述了一种基于关系数据库的工作流管理系统的设计与实现。该工作流管理系统不仅拥有工作流管理系统应有的前向调度、回退调度、用户任务列表的展示等功能,还有效地利用了关系数据库的成熟技术,节省了工作流管理系统的开发成本。     

演绎对象数据库SD-DOOD中继承性的实现算法

介绍了演绎对象数据库SD DOOD系统的结构,给出了系统中可以实现的继承方法以及与实现这些方法有关的模式、实例、查询算法,并对算法的时间复杂度进行了分析。实验结果表明算法是可行的和有效的。     

类——关系数据库之间的映射

面向对象的开发方法是目前软件开发的主要方法，它以类作为软件分析，设计和实现的基本单元，而关系数据库则是许多人都青睐的持久信息存储方法，所以类－－关系数据库之间的映射是开发者必须关注的一件大事，文章扼要地介绍了类－－关系数据库之间的映射原则。     

Panorama: A database system that annotates its answers to queries with their properties

When responding to queries, humans often volunteer additional information about their answers. Among other things, they may qualify the answer as to its reliability, and they may characterize it abstractly. This paper describes a relational database system that similarly annotates its answers with their properties. The process assumes that various assertions about properties of the data have been stored in the database (meta-information). These assertions are then used to infer properties of each answer provided by the system (meta-answers). Meta-answers are offered to users along with each answer issued, and help them to assess the value and meaning of the information that they receive. The advantages of the method described include: (1) It is extensible in that it allows users to determine the kinds of properties that the system will maintain and manipulate. (2) It has a built-in mechanism for determining the relevance of computed meta-information. (3) It is efficient: the number of operations required for meta-processing a given query can be expressed as a polynomial in the size of the meta-database. (4) It can be implemented externally with any commercial relational database system.     

A Survey of the Rule Language RL/1

In this paper we introduced the RL project which aims to integrate logic programming,relational databases and constraint solving in a single relational framework.We gave a summary of the architecture of the RL/1 system and shorth discussed the characteristics of the RL/1 language.A target of the project has become to turn the RL/1 system into an industrial strength database interface.     

可扩展的云关系型数据库的研究

为解决用户使用目前的云数据库服务时他们必须对应用做大量的修改的这种问题,在分析和研究现有的云数据库服务的基础上,提出了一种新型的云关系型数据库平台,它支持多语言开发的SDK机制,同时对数据的垂直、水平分布机制和算法进行了描述.描述了云关系型数据库的可靠性,包括数据存储管理和各种保护机制.仿真性能测试结果表明,在大海量数据量下,该云关系型数据库具有很好的可靠性、可扩展性和易用性.     

关系数据库性能优化研究

效率是数据库开发中经常遇到的问题，数据库性能的优劣将直接关系到软件的运行效率。为了提高数据库产品的性能，对影响关系数据库性能的一些主要因素进行了阐述。结合实际给出了数据库性能优化的一些建议并用实验数据证明之。分析和比较了不同设计方案可能对数据库性能的影响，提出了目前关于数据库性能优化的问题是没有通用方案的观点。     

关系数据库技术在计算机网络设计中的运用

随着我国社会经济建设水平的不断提高和计算机网络技术的推广普及,关系数据库技术在计算机网络设计中的运用成为社会各领域关注的焦点,本文将从关系数据库技术的角度出发,结合计算机网络设计的实际,对关系数据库技术在计算机网络设计中的运用进行深入的研究和探讨。     

A deductive object-oriented database system for situated inferencein law

Deductive object-oriented databases and situation theory are two important areas of research in the fields of databases and of linguistics. “AI and law” is a new field attracting both AI researchers and legal practitioners. Our research brings together the former two fields with the aim of designing knowledge applications in the latter. This is achieved through a formal model for legal reasoning, 𝒮ℳ (“Situation-theoretic Model”), and a deductive object-oriented database system, 𝒬𝒰ℐ𝒳𝒪𝒯ℰ. The purpose of this paper is to introduce the key features of this formal model, based on situation theory, and to describe how this database system can implement this abstract model for complex legal reasoning applications. Concrete examples from legal precedents are used to illustrate these advanced features     

The Glue-Nail deductive database system: Design,implementation, and evaluation

We describe the design and implementation of the Glue-Nail deductive database system. Nail is a purely declarative query language; Glue is a procedural language used for non-query activities. The two languages combined are sufficient to write a complete application. Nail and Glue code are both compiled into the target language IGlue. The Nail compiler uses variants of the magic sets algorithm and supports well-founded models. The Glue compiler's static optimizer uses peephole techniques and data flow analysis to improve code. The IGlue interpreter features a run-time adaptive optimizer that reoptimizes queries and automatically selects indexes. We also describe the Glue-Nail benchmark suite, a set of applications developed to evaluate the Glue-Nail language and to measure the performance of the system.Part of this article was presented at the ACM SIGMOD International Conference on Management of Data, Washington, DC, 1993.Much of this research was done while the authors were at Stanford University, Stanford, California, USA.