PB7.0通用任意字段查询技术的实现

查询是数据库管理系统中不可缺少的功能。本文给出一种在PB7．0下实现的可对任意指定的查询项日(对应一个数据窗口对象，可关联一个或多个数据库表)、按任意字段、任意指定条件进行纵向和横向组合查询并排序的技术。该技术新颖、独特，实现的查询模块简单、实用，可挂接到任何PB应用软件中，避免代码的重复编写，大大提高软件的开发效率。     

PB中一个通用查询控件的实现

本文介绍一种在PB下实现的可对指定的表、对所有字段、按任意指定条件进行组合查询的控件，该查询控件的一个突出特点是能自动取得并显示数据表中所有的字段及其相应的值。因而在查询界面中用户只需要选择查询的条件，控件自动转换为SQL查询语句；同时也支持用户直接输入查询条件，该查询可挂接在任意PB应用软件中。     

用Modify函数实现PB的组合查询和打印设置功能

在PB中,查询和打印是很常用到的。而巧用Modify函数可以实现组合查询和打印设置功能。下面所指库端均是阳本地SQL Anywhere库。建立应用、数据窗口等细致步骤,在此不再赘述。以下步骤均在PB上测试通过:     

基于PowerBuilder的通用查询的设计与实现

阐述了一种基于PowerBuilder实现可对指定的表、对所有字段、按任意指定条件进行组合通用查询的窗口.该通用查询特点在于能自动获取并显示数据表中所有的字段及其相应的值.因而在查询界面中用户只需选择或直接输入查询条件,控件可自动转换为相应的SQL查询语句.该查询模块可挂接在任意PowerBuilder应用软件中,具有一定实用价值.     

在PB9.0和Oracle 9i中实现多媒体数据操作的方法

阐述了多媒体数据库的实现方式，提出了在Oracle中或在PB 9．0中充分利用Oracle的包和PB的支持，LOB数据类型函数能很方便地实现多媒体数据操作。分别提出了Oracle的方法和PB对LOB数据类型存取的方法，并应用在了医疗保险软件中，效果反映良好。     

多线程技术下的Delphi通用查询编程

本文系统地介绍了使用多线程技术实现通用查询,并运用数据库技术、Delphi进行了编程实现.对于提高查询速度、实现软件代码的重用、增加应用系统的响应能力、增强应用系统的灵活性和伸缩性具有重要作用.     

基于PB的DAA构建普通高校招生管理信息系统

根据普通高校招生管理的现状,基于PowerBuilder(PB)的Distributed Application Architecture(DAA),构建了普通高校招生管理信息系统.本系统采用C/S结构实现招生信息数据的集中处理和B/S结构实现招生信息的任意查询;实现了业务内外划分,对内基于C/S结构实现各项内部业务功能,对外基于B/S结构访问WEB服务器.     

基于PowerBuilder的通用查询的设计与实现

阐述了一种基于PowerBuilder实现可对指定的表、对所有字段、按任意指定条件进行组合通用查询的窗口。该通用查询特点在于能自动获取并显示数据表中所有的字段及其相应的值。因而在查询界面中用户只需选择或直接输入查询条件，控件可自动转换为相应的SQL查询语句。该查询模块可挂接在任意PowerBuilder应用软件中，具有一定实用价值。     

PowerBuilder开发中的软件重用研究

通过模板技术、用户对象控件重用、全局函数重用和OLE对象重用技术在对PB开发中的软件重用进行研究,在PB开发环境中,应用这些软件重用技术可以提高编程效率、代码的通用性、模块的可重用性.     

SQL Server数据库组合查询的实现方法

应用软件的开发,要求设计人员能够实现数据库信息的组合查询功能,这是软件评价的重要指标之一,本文阐述了在客户服务器环境下,使用Powerbuilder语言编程,访问SQL Server数据库时组合查询的实现方法,着重介绍SQL语言的子查询方法和PB的过滤器方法。     

Making prolog more expressive

This paper introduces extended programs and extended goals for logic programming. A clause in an extended program can have an arbitrary first-order formula as its body. Similarly, an extended goal can have an arbitrary first-order formula as its body. The main results of the paper are the soundness of the negation as failure rule and SLDNF-resolution for extended programs and goals. We show how the increased expressibility of extended programs and goals can be easily implemented in any PROLOG system which has a sound implementation of the negation as failure rule. We also show how these ideas can be used to implement first-order logic as a query language in a deductive database system. An application to integrity constraints in deductive database systems is also given.     

基于XML数据的通用路径表达式的查询

查询重写是数据库研究的一个基本问题,它和查询优化、数据仓库、数据集成、语义缓存等数据库问题密切相关。同时,查询重写也是在关系数据库中存储和查询XML数据的关键问题。由于XML数据是元素嵌套和元素引用的,嵌套层数可以任意,并且模式和数据混合,因此XML的查询会涉及到广义路径表达式(GPE)。文中着重研究了如何解决XML数据的查询重写的方案,把含有广义路径表达式的XML查询语句重写为含有简单路径表达式(SPE)的XML查询语句,再转化为基于关系数据库的SQL语句。     

Visual spatio-temporal function-based querying

Visual interfaces are very important for human interactions in cyberworlds. Visual spatio-temporal querying should be one of the basic tools for data mining and retrieval in cyberworlds. In this paper, we propose a novel function-based query model for arbitrary shape spatio-temporal querying. The queries are defined as geometric shapes changing over time. In our model, data are interpreted geometrically as multidimensional points with time dimension or as moving points. The queries are formulated with geometric objects and operations over them to form the query solid changing over time. The proposed query model allows us to pose arbitrary shape spatio-temporal range queries. With the uniform geometric model we integrate visual mining and querying of time-dependent data employing 3D visualization tools. It allows for creating an intuitive visual interface using 2D projections of 3D query shapes. Our approach combines visualization of spatio-temporal data with visualization of the range query formulation employing very compact function-based query model. The implemented visual query system and its visual interface are proposed and described. An example of application of the system in analysis of simulation results in molecular dynamics is considered.     

An optimal access path handling strategy in a database environment

This paper presents an efficient access path storage and manipulation facility in a relational database management system. It includes an access path storage structure and an artificial intelligence which enables the DBMS to generate, store, and maintain paths which are more likely to be needed by random query requests. A model is developed for simulation, and several path delete strategies are simulated. Path delete strategies aiming for least recently used and least frequently used access paths are shown to require minimal DBA interference and to result in lowest average query processing cost. The proposed path handling strategy is sufficiently general to permit application in an arbitrary database system.     

FOCUS: A system for searching for multi-colored objects in a diverse image database

We describe a new multi-phase, color-based image retrieval system (FOCUS) which is capable of identifying multi-colored query objects in an image in the presence of significant, interfering backgrounds. The query object may occur in arbitrary sizes, orientations, and locations in the database images. Scale and rotation invariant color features have been developed to describe an image, such that the matching process is fast even in the case of complex images. The first phase of processing matches the query object color with the color content of an image computed as the peaks in the color histogram of the image. The second phase matches the spatial relationships between color regions in the image with the query using a spatial proximity graph (SPG) structure designed for the purpose. Processing at coarse granularity is preferred over pixel-level processing to produce simpler graphs, which significantly reduces computation time during matching. The speed of the system and the small storage overhead make it suitable for use in large databases with online user interfaces. Test results with multi-colored query objects from man-made and natural domains show that FOCUS is quite effective in handling interfering backgrounds and large variations in scale. The experimental results on a database of diverse images highlights the capabilities of the system.     

Semi-static operator graphs for accelerated query execution on FPGAs

This paper introduces the concept of Semi-static Operator Graphs (SOG) to provide a runtime reconfigurable accelerator for query execution based on a Field Programmable Gate Array (FPGA). Instead of generating an FPGA configuration for a given arbitrary query during system runtime, we deploy a general query structure on the FPGA consisting of multiple small reconfigurable partitions (RP). During deployment of the hybrid database system, for each RP various query operators are prepared as reconfigurable modules (RM). At system runtime, the proposed approach dynamically chooses and reconfigures RMs into the RPs regarding a given query. As a result the reconfiguration overhead during system runtime is significantly reduced and enables the utilization of our hybrid architecture in real-world scenarios.     

PeerCluster: A Cluster-Based Peer-to-Peer System

This paper proposes a cluster-based peer-to-peer system, called PeerCluster, for sharing data over the Internet. In PeerCluster, all participant computers are grouped into various interest clusters, each of which contains computers that have the same interests. The intuition behind the system design is that by logically grouping users interested in similar topics together, we can improve query efficiency. To efficiently route and broadcast messages across/within interest clusters, a hypercube topology is employed. In addition, to ensure that the structure of the interest clusters is not altered by arbitrary node insertions/deletions, we have devised corresponding JOIN and LEAVE protocols. The complexities of these protocols are analyzed. Moreover, we augment PeerCluster with a system recovery mechanism to make it robust against unpredictable computer/network failures. Using an event-driven simulation, we evaluate the performance of our approach by varying several system parameters. The experimental results show that PeerCluster outperforms previous approaches in terms of query efficiency, while still providing the desired functionality of keyword-based search.     

路网中移动对象快照K近邻查询处理

扩展了一种支持路网中移动对象的位置相关查询框架的功能,利用存在磁盘上的R树来存储网络连通性和一种基于内存的网格结构来维持移动对象的位置更新,提出了基于范围查询(MNDR)的快照K近邻查询算法(SKNN),对空间中的任意一条边,分析可能受影响的最大数量和最小数量的网格单元格,说明用于快照范围查询处理的搜索空间的最大范围,预估包含查询结果的子空间,使用这个子空间作为范围调用MNDR来有效地计算路网中查询点的KNN POI,降低I/O成本,缩短查询时间。通过实验对比,当规模扩展到数十万的移动对象时,SKNN比种有效查询处理空间网络数据的预计算方法S-GRID有更好大的系统吞吐量。     

Programming with logical queries, bulk updates, and hypotheticalreasoning

The paper presents a language of update programs that integrates logical queries, bulk updates and hypothetical reasoning in a seamless manner. There is no syntactic or semantic distinction between queries and updates. Update programs extend logic programs with negation in both syntax and semantics. They allow bulk updates in which an arbitrary update is applied simultaneously for all answers of an arbitrary query. Hypothetical reasoning is naturally supported by testing the success or failure of an update. We describe an alternating fixpoint semantics of update programs and show that it can express all nondeterministic database transformations