Transactional Information Systems is the long-awaited, comprehensive work from leading scientists in the transaction processing field. Weikum and Vossen begin with a broad look at the role of transactional technology in today's economic and scientific endeavors, then delve into critical issues faced by all practitioners, presenting today's most effective techniques for controlling concurrent access by multiple clients, recovering from system failures, and coordinating distributed transactions.


The authors emphasize formal models that are easily applied across fields, that promise to remain valid as current technologies evolve, and that lend themselves to generalization and extension in the development of new classes of network-centric, functionally rich applications. This book's purpose and achievement is the presentation of the foundations of transactional systems as well as the practical aspects of the field what will help you meet today's challenges.

* Provides the most advanced coverage of the topic available anywhere--along with the database background required for you to make full use of this material.
* Explores transaction processing both generically as a broadly applicable set of information technology practices and specifically as a group of techniques for meeting the goals of your enterprise.
* Contains information essential to developers of Web-based e-Commerce functionality--and a wide range of more "traditional" applications.
* Details the algorithms underlying core transaction processing functionality.

Table of Contents

PART ONE - BACKGROUND AND MOTIVATION
Chapter 1 What Is It All About?
Chapter 2 Computational Models
PART TWO - CONCURRENCY CONTROL
Chapter 3 Concurrency Control: Notions of Correctness for the Page Model
Chapter 4 Concurrency Control Algorithms
Chapter 5 Multiversion Concurrency Control
Chapter 6 Concurrency Control on Objects: Notions of Correctness
Chapter 7 Concurrency Control Algorithms on Objects
Chapter 8 Concurrency Control on Relational Databases
Chapter 9 Concurrency Control on Search Structures
Chapter 10 Implementation and Pragmatic Issues
PART THREE - RECOVERY
Chapter 11 Transaction Recovery 
Chapter 12 Crash Recovery: Notion of Correctness
Chapter 13 Page Model Crash Recovery Algorithms
Chapter 14 Object Model Crash Recovery
Chapter 15 Special Issues of Recovery
Chapter 16 Media Recovery
Chapter 17 Application Recovery
PART FOUR - COORDINATION OF DISTRIBUTED TRANSACTIONS
Chapter 18 Distributed Concurrency Control
Chapter 19 Distributed Transaction Recovery
PART FIVE - APPLICATIONS AND FUTURE PERSPECTIVES
Chapter 20 What Is Next?

Transactional Information Systems: Theory, Algorithms, and the Practice of Concurrency Control and Recovery

A multidatabase system (MDBS) is a facility that allows users access to data located in multiple autonomous database management systems (DBMSs). In such a system, global transactions are executed under the control of the MDBS. Independently, local transactions are executed under the control of the local DBMSs. Each local DBMS integrated by the MDBS may employ a different transaction management scheme. In addition, each local DBMS has complete control over all transactions (global and local) executing at its site, including the ability to abort at any point any of the transactions executing at its site. Typically, no design or internal DBMS structure changes are allowed in order to accommodate the MDBS. Furthermore, the local DBMSs may not be aware of each other and, as a consequence, cannot coordinate their actions. Thus, traditional techniques for ensuring transaction atomicity and consistency in homogeneous distributed database systems may not be appropriate for an MDBS environment. The objective of this article is to provide a brief review of the most current work in the area of multidatabase transaction management. We first define the problem and argue that the multidatabase research will become increasingly important in the coming years. We then outline basic research issues in multidatabase transaction management and review recent results in the area. We conclude with a discussion of open problems and practical implications of this research.

/pdf/overview-of-multidatabase-transaction-management-3w3j81jofr.pdf

Overview of multidatabase transaction management

Web Services are the most famous implementation of service-oriented architectures that has brought some challenging research issues. One of these is the composition, i.e., the capability to recursively construct a composite Web service as a workflow of other existing Web services, which are developed by different organizations and offer diverse functionalities (e.g., ticket purchase, payment), transactional properties (e.g., compensatable or not), and Quality of Service (QoS) values (e.g., execution price, success rate). The selection of a Web service, for each activity of the workflow, meeting the user's requirements, is still an important challenge. Indeed, the selection of one Web service among a set of them that fulfill some functionalities is a critical task, generally depending on a combined evaluation of QoS. However, the conventional QoS-aware composition approaches do not consider the transactional constraints during the composition process. This paper addresses the issue of selecting and composing Web services not only according to their functional requirements but also to their transactional properties and QoS characteristics. We propose a selection algorithm that satisfies user's preferences, expressed as weights over QoS criteria and as risk levels defining semantically the transactional requirements. Proofs and experimental results are presented.

/pdf/tqos-transactional-and-qos-aware-selection-algorithm-for-35y7s8lzxq.pdf

TQoS: Transactional and QoS-Aware Selection Algorithm for Automatic Web Service Composition

In recent years, numerous transaction models have been proposed to address the problems posed by advanced database applications, but only a few of these models are being used in commercial products. In this paper, we make the case that such models may be too centered around databases to be useful in real environments. Advanced applications raise a variety of issues that are not addressed at all by transaction models. These same issues, however, are the basis for existing workflow systems, which are having considerable success as commercial products in spite of not having a solid theoretical foundation. We explore some of these issues and show that, in many aspects, workflow models are a superset of transaction models and have the added advantage of incorporating a variety of ideas that have so far remained outside the scope of traditional transaction processing.

Advanced transaction models in workflow contexts

This paper presents a classification framework for workflow exception handling in the form of patterns. This framework is independent of specific modelling approaches or technologies and as such provides an objective means of delineating the exception-handling capabilities of specific workflow systems. It is subsequently used to assess the level of exceptions support provided by eight commercial workflow systems and business process modelling and execution languages. On the basis of these investigations, we propose a graphical, tool-independent language for defining exception handling strategies in workflows.

/pdf/workflow-exception-patterns-1ra1v0viay.pdf

Workflow exception patterns

A transaction model for multidatabase system (MDBS) applications in which global subtransactions may be either compensatable or retriable is presented. In this model compensation and retrying are used for recovery purposes. However, since such executions may no longer consist of atomic transactions, a correctness criterion that ensures that transactions see consistent database states is necessary. A commit protocol and a concurrency control scheme that ensures that all generated schedules are correct are also presented. The commit protocol eliminates the problem of blocking, which is characteristics of the standard 2PC protocol. The concurrency control protocol can be used in any MDBS environment irrespective of the concurrency control protocol followed by the local DBMSs in order to ensure serializability. >

A transaction model for multidatabase systems

A Multidatabase System (MDBS) is a collection of local database management systems, each of which may follow a different concurrency control protocol. This heterogeneity makes the task of ensuring global serializability in an MDBS environment difficult. In this paper, we reduce the problem of ensuring global serializability to the problem of ensuring serializability in a centralized database system. We identify characteristics of the concurrency control problem in an MDBS environment, and additional requirements on concurrency control schemes for ensuring global serializability. We then develop a range of concurrency control schemes that ensure global serializability in an MDBS environment, and at the same time meet the requirements. Finally, we study the tradeoffs between the complexities of the various schemes and the degree of concurrency provided by each of them.

The concurrency control problem in multidatabases: characteristics and solutions

The concept of serializability has been the traditionally accepted notion of correctness in database systems. However, in a heterogeneous distributed database system (HDBMS) environment, ensuring serializability is a difficult task mainly due to the desire of preserving the local autonomy of the participating local database systems. The authors introduce a new correctness criterion fur HDBMSs, two-level serializability (2LSR), and show that it preserves database consistency in several HDBMS models. Further, they present a simple protocol for ensuring that schedules in an HDBMS environment are 2LSR. This protocol is easily implementable and does not violate the local autonomy of sites. >

Non-serializable executions in heterogeneous distributed database systems

The concept of serializability has been traditionally accepted as the standard notion of correctness in database systems. However, in a multidatabase system (MDBS), ensuring serializability is a difficult task mainly due to the desire of preserving the autonomy of the participating local database systems. The authors introduce a new notion of correctness, RS-correctness, that is based on preserving the integrity constraints of the database. They present a new protocol for ensuring that schedules in an MDBS environment are RS-correct. The protocol preserves the local autonomy of sites. >

Sharad Mehrotra

Papers

A transaction model for multidatabase systems

The concurrency control problem in multidatabases: characteristics and solutions

Non-serializable executions in heterogeneous distributed database systems

Relaxing serializability in multidatabase systems

On Correctness of Nonserializable Executions