通用数据库查询系统的设计与实现

构造方便、有效的查询子系统是数据库应用系统设计的主要目标之一。本文在分析查询子系统一般设计要求的基础上，介绍了通用数据库查询系统ＧＱＳ的设计实现方法，应用ＧＱＳ，用户只须建立相应的工作库，就可以实现相应的查询子系统     

数据库组合查询与模糊查询的实现方法

本文以Ｆｏｘｂａｓｅ＾＋数据库为背景，介绍了实现组合查询和模糊查询的方法，并给出了较具体的实现策略，其设计思想及方法适用于其它数据库系统。     

能用查询系统的设计与实现

本文根据作者在实际数据库系统开发中，采用ＰｏｗｅｒＢｕｉｌｄｅｒ开发的一个通用查询系统，详细介绍了其设计与实现的思想。同时，也对大型数据库管理系统在设计时，如何考虑下载数据的查询，提供了一个好的解决方案。     

关系数据库汉语查询接口的设计与实现

汉语接口一直是我国AI界研究的热门课题之一。本文首先对汉语接口的可行性进行了论证, 然后在分析了自然查询语言功能特征的基础上, 提出了以词汇为基础, 以语义特征为先导的综合处理技术。为使接口能进行移植, 又引入了数据库模式字典, 设置移植和学习模块, 使之重建专用字典, 与新库连接。最后给出了实验系统的结构和流程图, 并作出该系统的性能评价和测试结果。     

综合查询系统的设计与实现

本文针对数据库应用系统中查询需求不断变化的问题,提出了一种综合查询的方法,用户可自定义查询内容和查询条件,由系统自动生成ＳＱＬ进行查询。     

基于XML的分布式数据库查询平台的设计与实现

针对当前分布式数据库的特点，该文通过应用XML技术，使用基于XML的XQuery作为查询语言，对用户提交的查询任务进行分析．分解成对各分布式数据库的子查询，并将各子查询结果进行处理返回给用户，实现对分布式数据库的有效查询。并在此基础上提出一个基于XML的分布式数据库查询方案，实现分布式数据库的协同查询处理。     

多数据库查询接口的设计与实现

MQI(multi-database query interface)是作者研制的、用SQL对多个RDBMS(relational database management system)数据源进行综合查询的客户端工具.该文主要讨论其逻辑结构与算法设计.     

Oracle＊Forms 4.5中查询功能的实现

本文详细介绍了Ｏｒａｃｌｅ＊Ｆｏｒｍｓ４．５中查询模式的功能，指出了其中所存在的子表不能对主表进行查询的问题。并对该问题给出一种行之有效的解决方法。     

Web数据库多表查询设计与实现

本文阐述了利用ASP技术与客户端脚本语言,实现在B/S模式下,对多表Web数据库的查询。其中包括界面设计,SQL语句的形成与优化,查询结果的显示与交互性方面的内容。     

Word中数据库动态查询与交互填写的编程实现

本文简要介绍了数据访问技术ＡＤＯ,并在Ｗｏｒｄ２０００中利用这一技术,运用ＶＢＡ编程建立数据库查询窗体模型,解决了在Ｗｏｒｄ表格中实现数据中动态查询与交互填写这一问题。     

An Image Database System with Support for Traditional Alphanumeric Queries and Content-Based Queries by Example

Large image databases are commonly employed in applications like criminal records, customs, plant root databases, and voters' registration databases. Efficient and convenient mechanisms for database organization and retrieval are essential. A quick and easy-to-use interface is needed which should also mesh naturally with the overall image management system. In this paper we describe the design and implementation of an integrated image database system. This system offers support for both alphanumeric query, based on alphanumeric data attached to the image file, and content-based query utilizing image examples. Content-based retrieval, specifically Query by Image Example, is made possible by the SHOSLIF approach. Alphanumeric query is implemented by a collection of parsing and query modules. All these are accessible from within a user-friendly GUI.     

The Farthest Spatial Skyline Queries

Pareto-optimal objects are favored as each of such objects has at least one competitive edge against all other objects, or “not dominated”. Recently, in the database literature, skyline queries have gained attention as an effective way to identify such pareto-optimal objects. In particular, this paper studies the pareto-optimal objects in perspective of facility or business locations. More specifically, given data points P and query points Q in two-dimensional space, our goal is to retrieve data points that are farther from at least one query point than all the other data points. Such queries are helpful in identifying spatial locations far away from undesirable locations, e.g., unpleasant facilities or business competitors. To solve this problem, we first study a baseline Algorithm TFSS and propose an efficient progressive Algorithm BBFS, which significantly outperforms TFSS by exploiting spatial locality. We also develop an efficient approximation algorithm to trade accuracy for efficiency. We validate our proposed algorithms using extensive evaluations over synthetic and real datasets.     

基于空间网络数据库的组最近邻居查询

组最近邻居查询是空间数据库在最近邻居查询上的新问题.目前,对组最近邻居查询的研究局限于欧氏空间,考察的只是对象间的相对位置关系,无法处理现实生活中对象间的连通性问题.鉴于此,本文基于空间网络数据库提出以网络距离为度量标准的组最近邻居查询概念,进而提出作为其算法基础的增量最近邻居查询算法INNN,最后构造出算法NMQM.
实验证明,NMQM是一种有效的组最近邻居查询算法.     

Aggregate Queries Over Conditional Tables

Conditional tables have been identified long ago as a way to capture unknown or incomplete information. However, queries over conditional tables have never been allowed to involve column functions such as aggregates. In this paper, the theory of conditional tables is extended in this direction, and it is shown that a strong representation system exists which has the closure property that the result of an aggregate query over a conditional table can be again represented by a conditional table. It turns out, however, that the number of tuples in a conditional table representing the result of an aggregate query may grow exponentially in the number of variables in the table. This phenomenon is analyzed in detail, and tight upper and lower bounds concerning the number of tuples contained in the result of an aggregate query are given. Finally, representation techniques are sketched that approximate aggregation results in tables of reasonable size.     

关系数据库的查询优化技术

查询优化是数据库管理系统设计和实现所采用的一项重要技术,也是影响数据库性能的关键因素。以实例为基础,结合数据库理论知识,对关系数据库查询优化策略从数据库设计、程序设计方面进行分析,并说明查询优化策略的具体应用。     

Deriving Object Oriented Federated Databases and Processing Federated Queries

In this paper, we present a federated query processing approach to evaluate queries on an Object-Oriented (OO) federated database. This approach has been designed and implemented in the OO-Myriad project, which is an OO extension to the Myriad FDBS researchmyriad:94. Since data integration is performed as part of federated query processing, we have proposed outerjoin, outer-difference and generalized attribute derivation operations together with the traditional relational operations, to be used for integration purposes. To define an OO federated database as a virtual view on multiple OO export databases, we adopt a database mapping strategy that systematically derives each of the class extents, deep class extents and relationships of the federated database using an operator tree consisting of the integration operations. By augmenting federated database queries with this algebraic mapping information, query execution plans can be generated. Based on the original Myriad query processing framework, we have realized the proposed OO federated query processing approach in the OO-Myriad prototype.     

关系数据库上基于元组组合的关键字查询

在传统的关系数据库上进行关键字查询已经成为近来数据库领域的研究热点,现有的工作都是以单个元组作为结果单元来返回.为了满足用户对于返回多元组的要求,提出了基于元组组合的关键字查询的概念,并通过返回元组组合来响应查询.通过对问题的分析得到了一系列启发式剪枝策略,设计了一个综合的优化算法.通过一系列真实数据集和人工数据集上的实验,验证了优化算法在绝大部分情况下比最初的算法在性能上有了显著的提高.     

Effcient Distributed Skyline Queries for Mobile Applications

In this paper, we consider skyline queries in a mobile and distributed environment, where data objects are distributed in some sites (database servers) which are interconnected through a high-speed wired network, and queries are issued by mobile units (laptop, cell phone, etc.) which access the data objects of database servers by wireless channels. The inherent properties of mobile computing environment such as mobility, limited wireless bandwidth, frequent disconnection, make skyline queries more complicat...     

空间数据库中全局最近邻查询处理方法

空间数据库中基于层次化索引结构的全局最近邻(all-nearest-neighbor, All-NN)计算采用单节点展开策略的嵌套循环技术来降低计算开销.在同一数据集合的全局最近邻计算中,基于索引结构带来的对象空间位置临近性特点,抛弃传统理论距离裁剪规则和嵌套循环技术来减少计算和索引节点访问开销.提出了采用局部计算和完备计算两阶段的计算模型来获得全局最近邻结果.首先以叶节点为单位,采用扫描线算法获得节点内部所有对象的局部最近邻结果,然后根据计算结果得到启发式裁剪距离.在第2阶段采用层次化过滤的范围查询算法来获取外部的(可能的)最近邻对象.实验与分析表明该方法可以很好地支持不同种类、大小、分布的数据集合All-NN查询处理,具有良好的实用价值.