Foreword

The more things change, the more they stay the same.

Last year, when the first edition of this book was released, IBM had just released an updated version of DB2 on the Linux, UNIX, and Windows platformsa version that was the most significant release to date, and one that provided new capabilities to reflect advances in the technology of both database systems and IT in general.

As I write this only a year later, IBM has once again just released an updated versions of the DB2 UDB product family; DB2 UDB for Linux, UNIX, and Windows, DB2 UDB for iSeries and DB2 UDB for zSeriessignificant new releases that include many new features and enhancements that make this the most advanced set of database products IBM has ever offeredand we believe the most advanced in the industry.

Unlike the first edition of the book, which covered only the Linux, UNIX, and Windows platforms, the second edition of this book covers SQL Procedural Language for the entire DB2 familythose platforms covered in the first edition, and now including DB2 for z-Series (OS/390) and i-Series (i5/OS) platforms. Additionally, this edition introduces a method for resolving performance issueshow to monitor and identify bottlenecks, and how to provide alternatives for resolution.

DB2 UDB is evolving to reflect the changing needs of the development community. Many of the new features in DB2 UDB are designed to significantly improve ease of use for the development community, including new autonomic capabilities than will help to change the role of the DBA. There have been many other areas of technical leadership that have been introduced in technical support; all have helped to propel DB2 into the leadership position in the database market.

Another such developer-oriented feature is the subject of the original edition of this publication; this updated second edition focuses on the updates and improvements for SQL PL in updated versions of DB2 UDB.

SQL PL for DB2 provides a high-level language to build portable application logic that has the potential for better performance and scalability, by virtue of exploiting server-side resources and eliminating client bottlenecks. Exploiting SQL PL can also serve to improve the manageability and security of applications by providing a more modular structure. The latest version of DB2 UDB on all platforms includes enhancements for stored procedure development that significantly increases usability, allowing more developers to experiment with writing these stored procedures. This updated edition discusses this enhancement in detail.

An important feature in the updated versions of DB2 is that SQL PL is now native in all versionsDB2 UDB is no longer dependent upon translation into C stored procedures. For you as a developer, you'll see increased productivity and faster performance from your applications. And, you'll see reduced costs of ownershipno more additional expenses from compilers or run-times.

Knowing how and when to exploit the many capabilities of SQL PL for DB2 is an important skill to developand the authors of this book are experts on the subject, as certified DB2 specialists.

They have done a very nice job in efficiently laying out the many benefits in an easy to understand fashion. They've covered all language elements of DB2 SQL PL, with a large number of examples and detailed explanations. They offer expert tips and best practices derived from experiences with real customers. Nowhere else will the reader find such a vast array of experience-driven tips; this book is the ultimate developer's resource for writing SQL procedures.

We at IBM are very proud of the success that we've seen with DB2, and we're grateful to our many partners, developers and customers who have chosen to build and run their solutions with our database product. Working together, we've built the industry's premiere database product and the broadest set of applications and solutions in the market.

We continue to listen intently to your needs and requirements, and have focused on addressing many of these requirements as DB2 continues to evolve. I know that the skills that you are about to learn or hone for SQL PL for DB2 will serve you well; on behalf of IBM, I look forward to a continuing relationship of delivering the industry's best solutions and applications.

Janet Perna

General Manager, Information Management

IBM Software Group