Book Image

IBM DB2 9.7 Advanced Application Developer Cookbook

Book Image

IBM DB2 9.7 Advanced Application Developer Cookbook

Overview of this book

With lots of new features, DB2 9.7 delivers one the best relational database systems in the market. DB2 pureXML optimizes Web 2.0 and SOA applications. DB2 LUW database software offers industry leading performance, scale, and reliability on your choice of platform on various Linux distributions, leading Unix Systems like AIX, HP-UX and Solaris and MS Windows platforms. This DB2 9.7 Advanced Application Developer Cookbook will provide an in-depth quick reference during any application's design and development. This practical cookbook focuses on advanced application development areas that include performance tips and the most useful DB2 features that help in designing high quality applications. This book dives deep into tips and tricks for optimized application performance. With this book you will learn how to use various DB2 features in database applications in an interactive way.
Table of Contents (15 chapters)
IBM DB2 9.7 Advanced Application Developer Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface

Creating a savepoint


The savepoints are used to divide a big transaction into smaller sub-transactions. It gives the developer the ability to do partial rollbacks, saving re-execution time. Multiple savepoints can be created in a transaction and we can roll back to any savepoint without affecting the processing done before the savepoint. In this recipe, we will see how to create a savepoint.

How to do it...

We can use a SAVEPOINT statement to create a savepoint. This statement can be embedded in any host language within a transaction:

SAVEPOINT svpnt_temp
UNIQUE
ON ROLLBACK RETAIN CURSORS
ON ROLLBACK RETAIN LOCKS

How it works...

  • UNIQUE: If this clause is specified, then we cannot create another savepoint with the same name until the savepoint is still active. We can always create more than one savepoint in multiple transactions. The savepoint level is started when the transaction starts, and finishes when the transaction completes.

  • ON ROLLBACK RETAIN CURSORS: The cursors are unaffected...