UpSizeR: Synthetically scaling an empirical relational database

The TPC benchmarks have helped users evaluate database system performance at different scales. Although each benchmark is domain-specific, it is not equally relevant to different applications in the same domain. The present proliferation of applications also leaves many of them uncovered by the very limited number of current TPC benchmarks.     

Implementation of an interactive relational graphics database

The benefits that accrue from the use of design database include (i) reduced costs of preparing data for application programs and of producing the final specification, and (ii) possibility of later usage of data stored in the database for other applications related to Computer Aided Engineering (CAE). An INTEractive Relational GRAphics Database (INTERGRAD) based on relational models has been developed to create, store, retrieve and update the data related to two dimensional drawings. INTERGRAD provides two languages, Picture Definition Language (PDL) and Picture Manipulation Language (PML). The software package has been implemented on a PDP 11/35 system under the RSX-11M version 3.1 operating system and uses the graphics facility consisting of a VT-11 graphics terminal, the DECgraphic 11 software and an input device, a lightpen.     

Beyond the relational database model

The relational model is a set-theoretic model for describing data constructs common in the business environment. Relational databases also minimize data duplication, which ensures data integrity and reduces storage requirements. Further, the relational model provides a way to represent variable-length constructs with fixed-length components. In addition, normalization theory is the basis of hundreds of papers and successful tenure applications. This ensured the academic community would carry the model forward. Finally, by following open standards, including the structured query language, vendors created a buzz with dozens of relational DBMS products such as System R, DB2, Oracle, SQL Server, Ingres, dBase, R:Base, Pearl, Paradox, and Access. An XDS have many advantages over a relational database, including seamless integration with user views as well as all the benefits of XML standards such as XML schema validation and the extensible stylesheet language for document materialization.     

Hierarchical to relational database migration

Although database migration has not yet been extensively researched, three predominant software solutions have evolved: language interfaces, source-code conversion, and data propagation. The authors consider how Swiss Bank and IBM designed and developed the IBM Data Propagator MVS/ESA, which supports interactive and batch data propagation. This software migrates data from the hierarchical IMS to the relational DB2, without affecting existing applications. It supports forward and reverse data propagation, which lets heterogeneous databases coexist. At Swiss Bank, the Data Propagator MVS/ESA handles the main customer and account databases at all five computer centers in Switzerland     

GRDB: A general purpose relational database system

This article discusses the design and development of GRDB (General Purpose Relational Data Base System) which has been implemented on a DEC-1090 system in Pascal. GRDB is a general purpose database system designed to be completely independent of the nature of data to be handled, since it is not tailored to the specific requirements of any particular enterprise. It can handle different types of data such as variable length records and textual data. Apart from the usual database facilities such as data definition and data manipulation, GRDB supports User Definition Language (UDL) and Security definition language. These facilities are provided through a SEQUEL-like General Purpose Query Language (GQL). GRDB provides adequate protection facilities up to the relation level. The concept of “security matrix” has been made use of to provide database protection. The concept of Unique IDentification number (UID) and Password is made use of to ensure user identification and authentication. The concept of static integrity constraints has been used to ensure data integrity. Considerable efforts have been made to improve the response time through indexing on the data files and query optimisation. GRDB is designed for an interactive use but alternate provision has been made for its use through batch mode also. A typical Air Force application (consisting of data about personnel, inventory control, and maintenance planning) has been used to test GRDB and it has been found to perform satisfactorily.     

Comments on an optimal set of indices for a relational database

M. Y. L. Ip et al., (see ibid., vol.SE-9, p.135-43, 1983) solved the index selection problem for a relational database by reducing it to a classical knapsack problem and then applying an approximation algorithm. It is shown that this reduction process does not work in general by providing a counterexample, and its practical significance is discussed. It turns out that the main idea of Ip et al. need not be discarded. In particular, the approximation algorithm used can be adapted fairly easily to take care of the problems which were raised by the counterexample. In spite of its simplicity, this modification can lead to a reduced number of indices, which is rather attractive from a practical point of view     

Numerical operations on a relational database

The problem is discussed of defining numerical operations on a relational database to accommodate the statistical analyses associated with a bivariate frequency table. An attempt has been made to extend Codd's relational algebra to include simple bivariate statistical operations preserving the closure of Codd's algebra. This extended algebra is applied to bivariate relational data structures needed for real-time automatic statistical quality control of a manufacturing process. Also discussed are some new category-numeric operations on relational tables     

一种新的关系数据库水印算法研究

针对现有水印算法的不足,提出了一种新的关系数据库水印算法.算法首先筛选出可以嵌入水印信息的属性并将他们划分为若干个等大的子集,然后将水印信息的每个二进制位嵌入到相应的子集中.水印检测依据的是中心极限定理,并且实现了水印信息的准确检测.最后通过SQL server进行仿真实验,验证此方法在现实应用中的有效性.     

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.     

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。     

SQLf: a relational database language for fuzzy querying

An important issue in extending database management systems functionalities is to allow the expression of imprecise queries to enable these systems to satisfy the user needs more closely. This paper deals with imprecise querying of regular relational databases. The basic idea is to extend an existing query language, namely SQL. In this context, two important points must be considered: one concerns the integration in the extended language of many propositions that have been made elsewhere, in particular those concerning fuzzy aggregation operators; and the second point is to know whether the equivalences which are valid in SQL still hold in the extended language. Both these topics are investigated in this paper     

Chabot: retrieval from a relational database of images

Selecting from a large, expanding collection of images requires carefully chosen search criteria. We present an approach that integrates a relational database retrieval system with a color analysis technique. The Chabot project was initiated at our university to study storage and retrieval of a vast collection of digitized images. These images are from the State of California Department of Water Resources. The goal was to integrate a relational database retrieval system with content analysis techniques that would give our querying system a better method for handling images. Our simple color analysis method, if used in conjunction with other search criteria, improves our ability to retrieve images efficiently. The best result is obtained when text-based search criteria are combined with content-based criteria and when a coarse granularity is used for content analysis     

计算机网络设计中关系数据库技术的应用

随着信息化技术的发展,计算机网络设计逐渐兴起并讯速发展。在计算机网络设计过程中,其工序相当复杂,因此需要建立与其相关的数据库保障计算机网络设计。关系数据库技术根据数据库中数据的相关性储存、调度数据,从而使其更好地服务于计算机网络设计。本文简要论述了关系数据库的概况、关系数据库在计算机网络设计中的辅助功能,分析了关系数据库技术在计算机网络设计中的基本原理并探讨了它在计算机网络设计中的优势。     

抽取XML文档到关系数据库

XML在关系数据库中的存储问题是XML研究领域中的一个重要问题。在总结多种映射方法的基础上,提出了一种方法将多个相似的XML文档进行解析,根据映射关系,生成各自的关系模式,并分析归纳出一个集成的关系模式,然后创建一个关系数据库,并在映射关系的基础上提取并存储XML文档数据到关系数据库。此方法以较为简洁的结构保存了XML文档的数据信息,其最大的特点就是不用考虑文档的模式信息（DTD,XML Schema）。并通过一个具体的实验结果来说明这种方法的有效性。     

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。     

利用XML视图更新关系数据库

XML已成为数据交换的一个重要介质,也被作为一个接口,即一个关系数据库的一个视图。此前,关于利用XML视图查询关系数据库(例如Silkroute)的问题有人已经做过深入探讨。对于关系数据库上XML视图的可更新性,首先考虑的是如何通过一个XML视图更新一个关系数据库的问题,把嵌套的关系代数作为一个关系数据库的XML视图,然后再考虑这个视图什么时候是可更新的问题。     

Intelligent simulation code generator: a relational database management approach

Although many studies have illustrated AI-based simulation, the concept of combining databases with AI and simulation is relatively new. Complementing AI and simulation with databases aids in the development of a completely integrated simulation environment that spans the whole simulation life cycle. This study illustrates the design of a simulation program generator, the intelligent simulation code generator (ISCG), which uses a database management system as the user-oriented interface, an object-oriented system to develop the knowledge base and simulation environment, and a target simulation language as the simulation software. The ISCG offers data independence, system independence, simulation-specific transparency, and target language neutrality. Furthermore, the ISCG offers system design flexibility.     

Uncertainty in a nested relational database model

Some database models have already been developed to deal with complex values but they have constrains that data stored is precise and queries are crisp. However, as many researchers have pointed out, there is a need to present, manipulate, and query complex and uncertain data of various non-traditional database applications such as oceanography, multimedia, meteorology, office automation systems, engineering designs, expert database systems and geographic information systems. In this paper, we present a logical database model, which is an extension of a nested relational data model (also known as an NF² data model), for representing and manipulating complex and uncertain data in databases. We also introduce a possible physical representation of such complex and uncertain values in databases and describe the query processing of the model that we discuss here.     

Inclusion and equivalence between relational database schemata

Conceptual relations among relational database schemata are investigated.Two different definitions of inclusion and a definition of equivalence between schemata are given.Several examples of practical situations adequately handled by our definitions are shown.Finally, necessary and sufficient conditions for inclusion and equivalence are proved for two classes of schemata, meaningful in the relational theory.