ABAP Performance Tuning

Hermann Gahm

• Publisher: SAP PRESS
• Year: 2009
• Print ISBN: 9781592292899
• eBook ISBN: 9781592295555
• Edition: 1
• Topic: Computer Science
• Subtopic: Computer Science General
• Index: Computer Science

This book is your guide for analyzing and optimizing ABAP source code (ABAP/4 and ABAP Objects). You'll learn about the analysis tools and performance-relevant technologies, and you'll discover how you can analyze existing source code and enhance your programming style. This is the resource you need to ensure that your ABAP programs are fully optimized. 1. Analysis Tools After reading this book, you'll know when and how to use analysis tools properly — includingCode Inspector, performance trace, ABAP trace, or single records statistics. 2. Programming Technologies Get detailed information on parallel processing, internal tables, SQL data processing, and muchmore, and learn how these technologies affect performance. 3. Buffering Explore the different buffers that are available onthe SAP NetWeaver Application Server ABAP, and learn the most important buffer options to avoid unnecessary database accesses. 4. Database Tuning You'll obtain a description of the database architecture and the technical background of databaseaccesses, and master the tuning options for database accesses. 5. New Developments Learn from a comprehensive overview of the new developments in ABAP Release 7.0, EhP2, such as Transaction SAT, the innovations of the performance trace, and changes of internal tables.

Highlights:

• Analysis Tools: Code and Memory Inspector, Selectivity and Process Analysis, Debugger, Performance Trace, ABAP Trace, E2E Trace, Single Records Statistics
• Parallel Processing
• Data Processing with SQL: Access Strategies, Resulting Set, Index Design, Execution Frequency, APIs
• Buffering: Buffering Types, Sessions, Shared Objects, Table Buffering
• Internal Tables: Table Types, Reading, Changing and Deleting Tables, Secondary Indexes, Nested Loops
• RFC Communication

ABAP performance tuning is an essential part of performance management for the development and maintenance of software.

1 Introduction

In computer science, the concept of performance usually describes the performance of a data processing system. It is used both for hardware and software.

For software, you usually use the two most critical metrics, response time and throughput, to describe the performance.

• Response time is the elapsed time between sending a request and receiving the results.
• Throughput generally refers to the data volume processed within a specific time unit (for example, order items per hour).

Another important property is the scalability of software. For example, a “good scalability” is present if an application requires twice the time for processing the double dataset. A “poor scalability” is if the double dataset requires an amount of time that was four times (or more) higher than usual.

Response time, throughput, and scalability are the most important goals of performance tuning.

1.1 Tuning Methods

This book focuses on the optimization of ABAP programs. Within the scope of performance management, you are provided with further options to achieve the mentioned goals whose characteristics and effects are briefly described in the following comparison to ABAP tuning.

ABAP tuning requires both expertise and time because it involves testing, among other things. With regard to expertise, you should have a sound technical understanding of the SAP NetWeaver Application Server, the ABAP programming language, and accesses to databases. Changes to ABAP applications always entail risks, which you must minimize through testing. The sphere of influence usually is limited to the optimization of the application, whereas positive effects, for example, in the form of released system resources, can also positively influence the entire system. The optimization of an ABAP application generally is a sustainable measure (for example, for increasing data volume).

Application tuning refers to an optimization of the application’s business logic. By means of application tuning, you can deactivate entire program parts that are not required for specific tasks or use alternative or more efficient data accesses, for example, to other tables. Application tuning is similar to ABAP tuning with regard to expertise, time requirement, sphere of influence, and risk. Regarding expertise, application tuning requires a more detailed knowledge of the application and the business process.

System tuning (system configuration, parameter changes, load distribution, and so on) requires yet another type of expertise and usually less time than the previously mentioned tuning methods. System tuning is the configuration of an SAP system. Changes to the configuration involve a certain risk that can be reduced through testing. System tuning changes not only affect an application but also the entire system or an application server.

The last method presented here is the adding of hardware . This approach is also playfully referred to as the kiwi approach (kiwi = kill it with iron). Some performance problems can — or, in some situations, must — be resolved by adding hardware. This approach usually requires less expertise. Time requirement, risk, and test effort depend on the type of hardware expansion. For example, system migration to another hardware platform can take a lot of time and test effort. Of course, more simple expansions, for example, main memory expansions, are not very comprehensive. Adding hardware is also a system- and application server-wide approach.

Successful performance management is characterized by taking and managing the right actions at the right time. Usually, successful performance management cannot be implemented with one single tuning method.

This book provides a detailed description of the ABAP performance tuning topic.

1.2 Structure of the Book

An understanding of the SAP system architecture forms the basis of ABAP tuning. Chapter 2 presents the architecture of SAP NetWeaver Application Server ABAP and details the performance-relevant aspects of this architecture.

Chapter 3 describes the use of the most essential tools available for ABAP performance analysis and provides general tips for performance analysis.

Chapter 4 outlines parallel processing. You will learn about prerequisites for parallelizable programs and the methods to parallelize programs.

Chapter 5 describes the tuning options for database accesses. For this purpose, you obtain a description of the database architecture and the technical background of database accesses. It details the execution of SQL statements using execution plans, the read data volume, bundling techniques for the reduction of executions, and further special topics, such as database- or database interface hints.

Chapter 6 describes the most important buffer options to avoid unnecessary database accesses. You will get to know the different buffers that are available on the SAP NetWeaver Application Server ABAP.

Chapter 7 outlines the performance-optimized processing of internal tables. It details the basic principles of the organization of internal tables and the performance-relevant aspects of their processing.

Chapter 8 discusses the data transfer to other systems via Remote Function Call (RFC). It outlines the most important performance aspects for RFCs.

Chapter 9 details further special topics that play roles in certain cases — for example, the local updates or parameter transfers — or are of secondary importance.

Chapter 10 provides an outlook of the essential innovations of some of the topics discussed.

Figure 1.1 shows a graphical display of the chapters.

Figure 1.1 Structure of the Book

1.3 How to Use This Book

Figure 1.1 indicates that you can read the book in two different ways.

The first way is to read the introduction and description of the architecture and then the analysis in Chapter 3. Here, you are presented with the most essential tools for performance analysis, and the respective results screens of the tools refer you to the background information and optimization options in Chapters 4 to 10. This way is advisable if you focus on the analysis of performance problems.

The second way is to first read the introduction and description of the architecture, and then read Chapter 4 to Chapter 9. This approach focuses on the optimization of ABAP coding and the background knowledge for the individual topics, not on performance analysis. This way is advisable if you are primarily interested in basic optimization techniques and background information for performance tuning.

The performance of an ABAP program also depends on the architecture of an SAP system. This chapter describes at which points the architecture plays a role for you as the ABAP developer.

2 SAP System Architecture for ABAP Developers

The followin...

Table of contents

• Notes on Usage and on the Screen Presentation
• Table of Contents
• Foreword
• Preface and Acknowledgments
• 1 Introduction
• 2 SAP System Architecture for ABAP Developers
• 3 Performance Analysis Tools
• 4 Parallel Processing
• 5 Data Processing with SQL
• 6 Buffering of Data
• 7 Processing of Internal Tables
• 8 Communication with Other Systems
• 9 Special Topics
• 10 Outlook
• A Execution Plans of Different Databases
• B The Author
• Index
• Service Pages
• Legal Notes