经济地理信息系统

经济地理信息系统是基于地理信息系统开发平台，实现对大量资源数据信息进行计算机管理与辅助决策的大型软件系统。它利用计算机技术、地理信息系统(GIS)技术，在现有的基础信息库的基础上，联系相关部门的业务需要，实现经济信息管理的科学化和自动化。     

High-Speed Tools for Global Information Management.II. Specifications and Uses of the Transparent Query Language (TQL) Part IIF. Additional Uses of TQL, Data Structures, Concise Definitions, Conclusions and Acknowledgments

This part, PART IIF [6], concludes the document HIGH-SPEED TOOLS FOR GLOBAL INFORMATION MANAGEMENT. II. Specifications and Uses of the Transparent Query Language (TQL) [1–6]. It describes novel applications of TQL, the key data structures, and contains a dictionary of Transparent Query Language terms. PART IIF references PART IIA [1], PART IIB [2], PART IIC [3], PART IID [4], and PART IIE [5] and contains Conclusions and Acknowledgements.     

Faster joins, self-joins and multi-way joins using join indices

We propose a new algorithm, called Stripe-join, for performing a join given a join index. Stripe-join is inspired by an algorithm called ‘Jive-join’ developed by Li and Ross. Stripe-join makes a single sequential pass through each input relation, in addition to one pass through the join index and two passes through a set of temporary files that contain tuple identifiers but no input tuples. Stripe-join performs this efficiently even when the input relations are much larger than main memory, as long as the number of blocks in main memory is of the order of the square root of the number of blocks in the participating relations. Stripe-join is particularly efficient for self-joins. To our knowledge, Stripe-join is the first algorithm that, given a join index and a relation significantly larger than main memory, can perform a self-join with just a single pass over the input relation and without storing input tuples in intermediate files. Almost all the I/O is sequential, thus minimizing the impact of seek and rotational latency. The algorithm is resistant to data skew. It can also join multiple relations while still making only a single pass over each input relation. Using a detailed cost model, Stripe-join is analyzed and compared with competing algorithms. For large input relations, Stripe-join performs significantly better than Valduriez's algorithm and hash join algorithms. We demonstrate circumstances under which Stripe-join performs significantly better than Jive-join. Unlike Jive-join, Stripe-join makes no assumptions about the order of the join index.     

On querying simple conceptual graphs with negation

We consider basic conceptual graphs, namely simple conceptual graphs (SGs), which are equivalent to the existential conjunctive positive fragment of first-order logic. The fundamental problem, deduction, is performed by a graph homomorphism called projection. The existence of a projection from a SG Q to a SG G means that the knowledge represented by Q is deducible from the knowledge represented by G. In this framework, a knowledge base is composed of SGs representing facts and a query is itself a SG. We focus on the issue of querying SGs, which highlights another fundamental problem, namely query answering. Each projection from a query to a fact defines an answer to the query, with an answer being itself a SG. The query answering problem asks for all answers to a query.

This paper introduces atomic negation into this framework. Several understandings of negation are explored, which are all of interest in real world applications. In particular, we focus on situations where, in the context of incomplete knowledge, classical negation is not satisfactory because deduction can be proven but there is no answer to the query. We show that intuitionistic deduction captures the notion of an answer and can be solved by projection checking. Algorithms are provided for all studied problems. They are all based on projection. They can thus be combined to deal with several kinds of negation simultaneously. Relationships with problems on conjunctive queries in databases are recalled and extended. Finally, we point out that this discussion can be put in the context of semantic web databases.     

基于XML＋DOM4J的数据库集成技术研究

如何实现数据库的集成、共享和利用，提高了信息系统的整体效能，以及解决了XML和数据库双向传输的瓶颈，成为信息支持系统的关键问题之一。该文在分析可扩展标记语言XML特点的基础上，对XML与数据库之间基于DOM模型的映射方式进行了探讨，并给出了以XML文件作为中间文件的异构数据库集成，以及XML文档和数据库之间数据传输的实现方法。     

提高Oracle数据查询速度的方法

为了提高数据库应用的性能，减少用户的等待时间，有必要对查询速度进行优化。本文以Orade数据库为例，首先分析了影响Orade数据查询速度的各种因素：数据库配置、数据库设计、应用程序的优化，然后基于这些因素提出了优化查询速度的方法，最后通过优化方法举例介绍了实际软件项目中应用的优化方法和策略。     

Preference update for e-commerce applications: Model,language, and processing

It is likely that customers issue requests based on out-of-date information in e-commerce application systems. Hence, the transaction failure rates would increase greatly. In this paper, we present a preference update model to address this problem. A preference update is an extended SQL update statement where a user can request the desired number of target data items by specifying multiple preferences. Moreover, the preference update allows easy extraction of criteria from a set of concurrent requests and, hence, optimal decisions for the data assignments can be made. We propose a group evaluation strategy for preference update processing in a multidatabase environment. The experimental results show that the group evaluation can effectively increase the customer satisfaction level with acceptable cost. Peng Li is the Chief Software Architect of didiom LLC. Before that, he was a visiting assistant professor of computer science department in Western Kentucky University. He received his Ph.D. degree of computer science from the University of Texas at Dallas. He also holds a B.Sc. and M.S. in Computer Science from the Renmin University of China. His research interests include database systems, database security, transaction processing, distributed and Internet computer and E-commerce. Manghui Tu received a Bachelor degree of Science from Wuhan University, P.R. China in 1996, and a Master Degree in Computer Science from the University of Texas at Dallas 2001. He is currently working toward the PhD degree in the Department of Computer Science at the University of Texas at Dallas. Mr. Tu’s research interests include distributed systems, grid computing, information security, mobile computing, and scientific computing. His PhD research work focus on the data management in secure and high performance data grid. He is a student member of the IEEE. I-Ling Yen received her BS degree from Tsing-Hua University, Taiwan, and her MS and PhD degrees in Computer Science from the University of Houston. She is currently an Associate Professor of Computer Science at the University of Texas at Dallas. Dr. Yen’s research interests include fault-tolerant computing, security systems and algorithms, distributed systems, Internet technologies, E-commerce, and self-stabilizing systems. She had published over 100 technical papers in these research areas and received many research awards from NSF, DOD, NASA, and several industry companies. She has served as Program Committee member for many conferences and Program Chair/Co-Chair for the IEEE Symposium on Application-Specific Software and System Engineering & Technology, IEEE High Assurance Systems Engineering Symposium, IEEE International Computer Software and Applications Conference, and IEEE International Symposium on Autonomous Decentralized Systems. She is a member of the IEEE. Zhonghang Xia received the B.S. degree in applied mathematics from Dalian University of Technology in 1990, the M.S. degree in Operations Research from Qufu Normal University in 1993, and the Ph.D. degree in computer science from the University of Texas at Dallas in 2004. He is now an assistant professor in the Department of Computer Science, Western Kentucky University, Bowling Green, KY. His research interests are in the area of multimedia computing and networking, distributed systems, and data mining.     

基于XML的数据映射技术

本文将Java技术与XML技术进行有机结合,研究了数据库操作中,XML技术映射数据库中表与Java类的方法,通过Java技术动态解析XML映射,为操作数据库建立对象查询语句,并应用Java技术对对象查询语句转换为标准SQL语句提出了新的实现方法。     

基于多重分类标准的关系模式异构性的研究

数据集成是解决信息孤岛问题的一个重要技术,它所面临的主要挑战是如何有效地处理多个数据源之间的分布性、自治性和异构性.分析研究了在不同数据源之间由多重分类标准而产生的异构性并对其进行形式化描述,然后在形式化描述的基础上给出了一个通用的查询转换算法以解决该种形式的异构性.     

Well-definedness and semantic type-checking for the nested relational calculus

The well-definedness problem for a programming language consists of checking, given an expression and an input type, whether the semantics of the expression is defined for all inputs adhering to the input type. A related problem is the semantic type-checking problem which consists of checking, given an expression, an input type, and an output type whether the expression always returns outputs adhering to the output type on inputs adhering to the input type. Both problems are undecidable for general-purpose programming languages. In this paper we study these problems for the Nested Relational Calculus, a specific-purpose database query language. We also investigate how these problems behave in the presence of programming language features such as singleton coercion and type tests.