面向对象数据库的C宿主语言接口实现技术

面向对象的数据库管理系统（ＯＯＤＢＭＳ）通常都具备自身的查询语言，它以交互的方式供用户进行数据定义与数据操纵．除此之外，它还必须为程序员提供可在Ｃ、ＦＯＲＴＲＡＮ、ＰＡＳＣＡＬ等高级语言里嵌入使用查询语言的宿主语言接口．本文首先介绍这样一种Ｃ宿主语言接口Ｃ—ＯＳＤＬ，而后重点讨论它的实现技术，尤其是将Ｃ—ＯＳＤＬ命令转换成ＳＱＬ语句的翻译算法以及使用ＳＱＬ实现支持导航式查找的指针层次管理方法．文中讨论的Ｃ—ＯＳＤＬ实现技术以及最初的接口设计是面向对象的数据库技术的深入探讨．     

开放数据库互连在电厂管理信息系统中的应用研究

本文针对管理信息系统开发过程中传统的数据库管理系统的不足，提出使用被各数据库厂商所支持的ＯＤＢＣ接口，使应用程序能相对独立于各数据库产品，实现信息的集成与共享。文中着重论述了ＯＤＢＣ的运行机制和在实际工程中的应用。     

客户端开发工具与服务器端数据库的互连

本文介绍了客户／服务器模式下客端开发工具与服务器端数据库互连的原理，分析了Ｐｏｗｅｒｂｕｉｌｄｅｒ所支持的两种数据库接口ＯＤＢＣ和专用接口的特点，最后通过ＰＢ与ＮＴＳＱＬ互连的事例阐述了连接的方法。     

运用VB的数据控件编制小型ODBC数据库系统

数据控件是ＶＢ３．０标准版／专业版中提供的进行数据库管理的专用工具，在ＶＢ的三种数据库实现方法中运用最简便，编码量少，在小型的ＯＤＢＣ数据库系统中尤其适用。本文结合一些实例具体阐述了运用数据控件及绑定控制项编制小型ＯＤＢＣ数据库系统的实现步骤、方法和技巧。     

在客户／服务器结构中利用ODBC访问数据库的两种方法

ＯＤＢＣ量种数据库与应用程序之间的调用级别接口。与嵌入式ＳＱＬ和ＰＬ／ＳＱＬ相比,ＯＤＢＣ程序开发具有更强的数据库独立性,因此,在客户／服务器结构中,常常使用ＯＤＢＣ作为客户机与服务器之间的接口部分。主要讨论了利用ＯＤＢＣ访问数据库的两种方法。     

DOS图形用户接口GUI设计

作者在Ｃ环境下设计了一个ＤＯＳ图形用户接口ＧＵＩ，它为ＤＯＳ提供了绘图和显示特殊文字的图形服务功能。本文介绍了在Ｃ环境下的ＤＯＳ图形用户接口设计方法，以及ＦＯＸＢＡＳＥ＋数据库系统和其它语言编写的应用程序与ＧＵＩ的接口设计。     

Oracle与PowerBuilder的开发技术

结合Ｃ／Ｓ或Ｂ／Ｓ结构企业管理信息系统的设计与实施,对操作系统为Ｗｉｎｄｏｗｓ ＮＴ、数据库系统为Ｏｒａｃｌｅ、开发工具为ＰｏｗｅｒＢｕｉｌｄｅｒ６的开发环境下的数据局部化、前后台协调、ＯＤＢＣ及数据库专用接口、存储过程和函数及触发器的使用、减少数据冗余和查询优化等技术进行了详细介绍。     

数据库开发工具POWERBUILDER与ODBC接口

ＯＤＢＣ是个通用数据库接口，ＰｏｗｅｒＢｕｉｌｄｅｒ是数据库开发工具，本文分析ＯＤＢＣ的结构，并描述了用ＰｏｗｅｒＢｕｉｌｄｅｒ通过ＯＤＢＣ接口进行数据库开发的接口设置。     

Z系统中开放数据库接口模块Z—ODIM的设计与实现

Ｚ系统中开放数据库接口模块Ｚ－ＯＤＩＭ的研制目的主要有两点：其一是实现其支撑数据库系统的开放性，以适应不同用户的需求；其二是实现信息共享性，以支持合作计算。文中详细论述了Ｚ－ＯＤＩＭ的体系结构和实现技术。     

ODBC技术在ObjectARX程序中的应用

简要介绍了ＯＤＢＣ的工作原理,主要探讨了在基于ＭＦＣ的ＯｂｊｅｃｔＡＲＸ应用程序中运用ＯＤＢＣ的方法,利用ＭＦＣ数据库类和直接采用ＯＤＢＣ函数两种方法实现对数据库的操作,给出了部分应用实例。     

多库系统的两阶段局部代理失败恢复策略

从保证全局事务的ACID性及实际的可操作性出发，提出了一种较为可靠的两阶段局部代理的工作流程，使用局部代理作为全局事务管理系统与局部数据库的中间层，模拟出符合2PC协议的状态，从而在多数据库的事务处理中使用2PC协议，在最大限度保证异构数据库自治的前提下，从一定程度上解决了全局事务的原子性保证问题和局部站点失败恢复的问题     

Transaction management issues in a failure-prone multidatabase system environment

This paper is concerned with the problem of integrating a number of existing off-the-shelf local database systems into a multidatabase system that maintains consistency in the face of concurrency and failures.The major difficulties in designing such systems stem from the requirements that local transactions be allowed to execute outside the multidatabase system control, and that the various local database systems cannot participate in the execution of a global commit protocol. A scheme based on the assumption that the component local database systems use the strict two-phase locking protocol is developed. Two major problems are addressed: How to ensure global transaction atomicity without the provision of a commit protocol, and how to ensure freedom from global deadlocks.     

On Concurrency Control in Multidatabase Systems with an Extended Transaction Model

A major concurrency control problem that we have to cope in multidatabase systems is the global deadlock detection and resolution problem. This detection must take into account the autonomy of local systems, which make impossible the visibility of the state of local transactions. A well-known approach to detect such deadlocks, called potential global deadlocks, is one based on the potential conflict graph (PCG) appropriate for the multidatabase transaction model with a global commit protocol. This classical transaction model is very constraining for applications manipulating great volumes of information, and where subtransaction terminations (commit or abort) of global transactions are not totally dependant. In this paper we present an effective potential global deadlock characterization, and an efficient potential global deadlock detection algorithm, in multidatabase systems with an extended transaction model more suited for such applications.     

An extended transaction to maintain consistency and recovery in multidatabase systems

A complete practical solution to transaction management preserving multidatabase consistency in the presence of multidatabase updates and failures is presented. The approach developed does not require support for the two-phase commit (2PC) protocol in the participating local database management systems (LDBMSs). Furthermore, it does not violate local autonomy; the source code of the LDBMSs is not modified in any way and the multidatabase system (MDBS) does not access or modify any control information of the LDBMS. The principles of the 2PC protocol in the process of global transaction commitment are adopted. The presented method does not rely on any specific concurrency control mechanism for LDBMSs. Consideration is given to global transaction failures due to subtransaction aborts by the LDBMSs and local site crashes. The recovery process is based on undo operations. While a global transaction is in progress, the tables accessed by subtransactions of this transaction at each local site are locked using specially initiated table locks. These locks are stored and maintained in the local database itself as control tables. The approach taken is easy to implement, and its limitations are discussed.     

Using tickets to enforce the serializability of multidatabasetransactions

To enforce global serializability in a multidatabase environment the multidatabase transaction manager must take into account the indirect (transitive) conflicts between multidatabase transactions caused by local transactions. Such conflicts are difficult to resolve because the behavior or even the existence of local transactions is not known to the multidatabase system. To overcome these difficulties, we propose to incorporate additional data manipulation operations in the subtransactions of each multidatabase transaction. We show that if these operations create direct conflicts between subtransactions at each participating local database system, indirect conflicts can be resolved even if the multidatabase system is not aware of their existence. Based on this approach, we introduce optimistic and conservative multidatabase transaction management methods that require the local database systems to ensure only local serializability. The proposed methods do not violate the autonomy of the local database systems and guarantee global serializability by preventing multidatabase transactions from being serialized in different ways at the participating database systems. Refinements of these methods are also proposed for multidatabase environments where the participating database systems allow schedules that are cascadeless or transactions have analogous execution and serialization orders. In particular, we show that forced local conflicts can be eliminated in rigorous local systems, local cascadelessness simplifies the design of a global scheduler, and that local strictness offers no significant advantages over cascadelessness     

移动分布式数据库中的实时事务处理

提出了移动事务实时提交协议(MTRTC)和多版本乐观并发控制协议(MVOCC)处理移动分布式实时事务。MVOCC有效性检查分为局部有效性检查和全局有效性检查，采用动态调整串行次序，避免了不必要的事务重启动，改善了只读事务的响应时间。MTRTC是一个实时提交协议，减少了通信信息。实验结果表明结合MVOCC和MTRTC事务处理协议优于其它事务处理协议。     

Commit protocols for externalized-commit heterogeneous database systems

In designing a heterogeneous database systems, one of the main technical challenges is developing techniques for ensuring global commit. That is, guaranteeing that a transaction spanning multiple individual database management systems (DBMSs) either commits at all the participating DBMSs or at none of them. Previous work in this area typically assumes that the participating DBMSs do not provide a mechanism for interacting with their commit facilities. While this is true in many cases, in practice there are systems which support a programmatic interface to their commit protocols. We refer to database systems offering such facilities asexternalized commit DBMSs.The focus of this paper is on commit protocols for these systems. We propose two new commit protocols for externalized commit DBMSs. The first may be used to obtain global commit in heterogeneous database systems composed of DBMSs with different 2-phase commit protocols (e.g., centralized and linear). The second protocol is more general, and ensures global commit even if the participating DBMSs employ 3-phase commit protocols. The more general protocol also preserves database autonomy, since it does not block a DBMS upon failure of another system. We describe both protocols in detail and prove their correctness. Recommended by: M. RusinkiewiczThis work was partially supported by an IBM Research Initiation Grant.     

Database migration: a new architecture for transaction processingin broadband networks

Due to recent developments in network technologies, broader channel bandwidth is becoming prevalent in worldwide networks. As one of the new technologies making good use of such broadband channels, dynamic relocation of databases through networks, database migration, will soon be used in practice as a powerful and basic database operation. We propose two transaction processing methods to take advantage of database migration in broadband networks. These methods choose the most efficient transaction processing method between the conventional method, based on the two-phase commit protocol, and our method, using database migration. We also propose a concurrency control mechanism and a recovery mechanism for our proposed methods. Simulation results are presented comparing the performance of our proposed methods and the conventional transaction processing method based on the two-phase commit protocol. The results demonstrate that the effective use of database migration produces better performance than the conventional method     

Application Specific Transaction Management in Multidatabase Systems

We present a transaction model for multidatabase systems with autonomous component systems, coined heterogeneous 3-level transactions. It has become evident that in such a system the requirements of guaranteeing full ACID properties and full local autonomy can not be reconciled. In the heterogeneous 3-level transaction model, semantics of actions and specific properties of the architecture of multidatabase systems and of applications are utilized to define application specific compromises between these competing goals. We consider different definitions of conflicts between actions together with application specific sets of allowed (autonomous) local transactions and global subtransactions. A formal model for serializability is given. It is proven that heterogeneous 3-level transactions guarantee all consistency constraints that are ensured in serial executions. In contrast to most other models, we do not require data to be partitioned into global and local data. In particular, heterogeneous 3-level transactions even allow the same data to be updated by local and global transactions in parallel, if these updates are found to be semantically non-conflicting. Recovery is handled by inverse actions. We present a formal framework for this approach which is fully integrated into serializability theory by considering inverse actions as ordinary actions. This has an important impact on the relationship of concurrency control and recovery in our model: By changing the definition of conflicts between actions in order to tailor the model according to application needs, recovery is implicitly affected and no further explicit adaptation of recovery algorithms is necessary. The heterogeneous 3-level transaction model assumes component database systems to support ACID transaction properties. Further properties of local transactions or interfaces of the component database systems are not required. We describe a prototype implementation of heterogeneous 3-level transactions in the object-oriented database system VODAK.     

基于事务语义的多数据库系统并发存取控制方法

本文提出了一种多数据库系统（MDBS）的基于事务语义的并发存取控制方法。文中首先按对数据库一致性的影响将事务分类;接着提出了新的MDBS的并发调度的非可串行正确性准则;然后;叙述了称为“事务语义协议”的并发存取控制原理和方法,给出了全局调度和交付的算法和方法正确性证明。