CIMS环境下的数据库管理系统

针对ＣＩＭＳ环境对数据库管理系统（ＤＢＭＳ）的需求，对ＤＢＭＳ的开放性、安全及可靠性及分布式处理进行分析。提出了目前ＣＩＭＳ环境下ＤＢＭＳ应采用具有客户／服务器体系结构数据库管理系统     

分布式工程数据库管理系统dEDBMS

随着ＣＡＤ／ＣＡＭ等工程应用的逐步深入，对具有分布式管理功能的工程数据库管理系统的需求日益迫切。为此，在我室自行研制的单用户工程数据为核心管理系统ＥＤＢＭＳ／２的基础上，欠设计并实现了一个分布式工程数据库管理系统－－－ｄＥＤＢＭＳ。ｄＥＤＢＭＳ运行在ＳＵＮ ＴＣＰ／ＩＰ网络环境，基于作者提出的扩展客户／服务器体系结构。针对工程应用之特点，提供远程数据库访问和检出／检入两种操作模式，支持多服务器的自     

PowerBuilder＋INFORMIXC／S开发环境的建立

本文分析了用ＰｏｗｅｒＢｕｉｌｄｅｒ作前端工具，ＩＮＦＯＲＭＩＸ作后端ＤＢＭＳ时，建立客户／服务器开发环境的解决方案。     

开放式数据库应用快速开发平台的设计与实现

本文阐述了开放式数据库应用快速开发平台软件的设计思想、实现原理和构造方法；提出了“开放式开发工具”要基于客户／服务器结构、独立于ＤＢＭＳ和支持多种ＤＢＭＳ互连、支持三级模式和具有统一的用户界面等原则；设计和部分实现了符合上述原则的开放式数据库应用快速开发平台软件。作为第一阶段成果，设计与实现了联接Ｓｙｂａｓｅ的Ｆｏｘｐｒｏ快速开发平台的商品化软件产品。     

开放式数据库应用快速开发平台的设计与实现

本文阐述了开放式数据库应用快速开发平台软件的设计思想，实现原理和构造方法；提出了“开放式开发工具”要基于客户／服务器结构，独立于ＤＢＭＳ和支持多种ＤＢＭＳ互连，支持三级模式和具有统一的用户界面等原则；设计和部分实现了符合上述原则的开放式数据库应用快速开发平台软件。作为第一阶段成果，设计与实现了联接Ｓｙｂａｓｅ的Ｆｏｘｐｒｏ快速开发平台的商品化软件产品。     

数据库管理系统LNE—DBMS的设计与实现

ＬＮＥ－ＤＢＭＳ是我们自己设计和实现的一个数据库管理系统，它采用了客户／服务器计算模型，多线程结构等不少先进的设计思想，以及简明有效的实现方案，整个系统独具独色，本文介绍了其具体实现方法。     

用OLE自动化在应用程序中嵌入MapInfo地图功能

本文针对在Ｄｅｌｐｈｉ下开发配电网地理信息系统（ＧＩＳ）的背景,介绍了如何在Ｄｅｌｐｈｉ应用程序中嵌入ＭａｐＩｎｔｆｏ地图功能。为了实现Ｄｅｌｐｈｉ与ＭａｐＩｎｆｏ之间的消息传递,必须创建ＭａｐＩｎｆｏ端自动化服务器用于执行ＭａｐＢａｓｉｃ程序以及Ｄｅｌｐｈｉ端自动化服务器用于捕获来自地图窗口的消息。通过ＯＬＥ自动化客户／服务器的一整套机制,就可以比较方便地开发出基于Ｄｅｌｐｈｉ的地理信息系统,实     

客户／服务器系统前端开发技术

该文主要讨论了客户／服务器系统的结构,广泛应用的原因及其优点,并以ＳＱＬ Ｓｅｒｖｅｒ的存储过程和触发器,ＰｏｗｅｒＢｕｉｌｄｅｒ为例说明功能强大的ＤＢＭＳ和前端开发工具保证了客户／服务器系统的优越性能。并介绍了Ｐｏｗｅｒｂｕｉｌｄｅｒ的一些技术特点,客户端应用软件在实际应用中的几种查询方式,以及实现主／明细窗口的技术要求,并用ＰｏｗｅｒＢｕｉｌｄｅｒ建立了一个通用的、主表可更新的主／明细数据录主     

Windows ODBC与多数据源

本文介绍ＯＤＢＣ的概念及其体系结构，描述了客户／服务器结构及其本原理，阐述了ＳＱＬ Ｓｅｒｖｅｒ、ＯＲＡＣＬＥ７在Ｗｉｎｄｏｗｓ环境下，ＯＤＢＣ的实现方法。     

在UNIX／SYBASE环境下用DB—Library／C库进行前端程序设计的基本方法

在ＵＮＩＸ／ＳＹＢＡＳＥ环境下用ＤＢ－Ｌｉｂｒａｒｙ／Ｃ库进行前端程序设计的基本方法刘杰张健（山东省计算中心济南２５００１４）收稿日期：１９９７年７月１８日１客户／服务器方式与ＳＹＢＡＳＥ数据库客户／服务器方式是一种体系结构，它的实质就是在客户和服务...     

Performance comparison of three modern DBMS architectures

The introduction of powerful workstations connected through local area networks (LANs) inspired new database management system (DBMS) architectures that offer high performance characteristics. The authors examine three such software architecture configurations: client-server (CS), the RAD-UNIFY type of DBMS (RU), and enhanced client-server (ECS). Their specific functional components and design rationales are discussed. Three simulation models are used to provide a performance comparison under different job workloads. Simulation results show that the RU almost always performs slightly better than the CS, especially under light workloads, and that ECS offers significant performance improvement over both CS and RU. Under reasonable update rates, the ECS over CS (or RU) performance ratio is almost proportional to the number of participating clients (for less than 32 clients). The authors also examine the impact of certain key parameters on the performance of the three architectures and show that ECS is more scalable that the other two     

Communication Architectures for Massive Multi-Player Games

Massive multi-player games are characterized by a large number of participating players. It is therefore essential that an appropriate communication architecture is deployed in order to support an ever growing number of players. Several such architectures have been proposed, including client-server and peer-to-peer architectures. In this paper, we propose a systematic method to assess the scalability of different architectures in order to identify the most appropriate one for specific game types. The model proposed is very general in that it covers centralized, distributed, and hybrid architectures and it is applied to the client-server, peer-to-peer and the newly introduced federated peer-to-peer architecture. Quantitative expressions that capture the effect of various game types are derived, and the trade-offs among the architectures are identified.     

Network Security for Client-Server Architecture Using Wiretap Codes

We propose a method that provides information-theoretic security for client-server communications. By introducing an appropriate encoding scheme, we show how a client-server architecture under active attacks can be modeled as a binary-erasure wiretap channel. The secrecy capacity of the equivalent wiretap channel is then used as a metric to optimize the architecture and limit the impact of the attacks. Upper and lower bounds of the optimal secrecy capacity are derived and analyzed. While still mostly of theoretical interest, our analysis sheds some light on the practical design of resistant and secure client-server architectures.      

Audio support for an object-oriented database-management system

We describe the development of the data type audio in an object-oriented database management system (DBMS). The interface of the data type includes operations to store, retrieve, and manipulate audio data. Additionally, a transport protocol supports continuous recording and presentation at the users' workstations in a client-server environment. Design considerations are outlined and lead us to use no compression algorithms and to handle parametrized sample rates and sizes transparently for the user. Specific manipulation operations, such as low-pass filtering and dynamic compression, are described in detail. The implementation of an interactive audio tool shows that the data type audio can be used in the same way as conventional data types. We give an outlook on further built-in support of time-dependent media that a comprehensive multimedia DBMS should offer.     

An Efficient Synchronization Mechanism for Mirrored Game Architectures

Existing online multiplayer games typically use a client-server model, which introduces added latency as well as a single bottleneck and single point of failure to the game. Distributed multiplayer games minimize latency and remove the bottleneck, but require special synchronization mechanisms to provide a consistent game for all players. Current synchronization methods have been borrowed from distributed military simulations and are not optimized for the requirements of fast-paced multiplayer games. In this paper we present a new synchronization mechanism, trailing state synchronization (TSS), which is designed around the requirements of distributed first-person shooter games.We look at TSS in the environment of a mirrored game architecture, which is a hybrid between traditional centralized architectures and the more scalable peer-to-peer architectures. Mirrored architectures allow for improved performance compared to client-server architectures while at the same time allowing for a greater degree of centralized administration than peer-to-peer architectures.We evaluate the performance of TSS and other synchronization methods through simulation and examine heuristics for selecting the synchronization delays needed for TSS.     

适用移动数据库的客户／服务器体系统结构研究

讨论了比较了两级和多级客户／服务器结构的优缺点,还介绍了适于移动数据库的两种多级客户／服务器结构,在此基础上提出了一种移动数据库管理系统的体系结构,并给出了其功能组成。     

Network-based visualization of 3D landscapes and city models.

To improve the visualization of large 3D landscapes and city models in a network environment, the authors use two different types of hierarchical level-of-detail models for terrain and groups of buildings. They also leverage the models to implement progressive streaming in both client-server and peer-to-peer network architectures.     

Object-oriented DBMS requirements

The requirements on an object-oriented DBMS for management of information in a large, complex enterprise are presented. These requirements aid in the achievement of an environment characterized by data sharing, open architectures, application and data portability, and assurance of data integrity. They were defined from the point of view of a user of the DBMS; therefore they describe the expected functionality of the DBMS and do not specify the method of implementation to achieve this functionality. They encompass requirements on the data model, query and data manipulation languages, the system architecure, interfaces to the system, change management, and transaction management.     

Distributed Multi-Level Recovery in Main-Memory Databases

In this paper we present recovery techniques for distributed main-memory databases, specifically for client-server and shared-disk architectures. We present a recovery scheme for client-server architectures which is based on shipping log records to the server, and two recovery schemes for shared-disk architectures—one based on page shipping, and the other based on broadcasting of the log of updates. The schemes offer different tradeoffs, based on factors such as update rates.Our techniques are extensions to a distributed-memory setting of a centralized recovery scheme for main-memory databases, which has been implemented in the Dalì main-memory database system. Our centralized as well as distributed-memory recovery schemes have several attractive features—they support an explicit multi-level recovery abstraction for high concurrency, reduce disk I/O by writing only redo log records to disk during normal processing, and use per-transaction redo and undo logs to reduce contention on the system log. Further, the techniques use a fuzzy checkpointing scheme that writes only dirty pages to disk, yet minimally interferes with normal processing—all but one of our recovery schemes do not require updaters to even acquire a latch before updating a page. Our log shipping/broadcasting schemes also support concurrent updates to the same page at different sites.     

Secure spread: an integrated architecture for secure group communication

Group communication systems are high-availability distributed systems providing reliable and ordered message delivery, as well as a membership service, to group-oriented applications. Many such systems are built using a distributed client-server architecture where a relatively small set of servers provide service to numerous clients. In this work, we show how group communication systems can be enhanced with security services without sacrificing robustness and performance. More specifically, we propose several integrated security architectures for distributed client-server group communication systems. In an integrated architecture, security services are implemented in servers, in contrast to a layered architecture, where the same services are implemented in clients. We discuss performance and accompanying trust issues of each proposed architecture and present experimental results that demonstrate the superior scalability of an integrated architecture.