Preface Authors Db2 12 for IBM z/OSfi delivers several significant business values, such as cost reductions,  scalability improvement, and improved application enablement for cloud and mobile  environment.  Db2 12 also introduces a foundation of continuous delivery. In continuous delivery, new  capabilities and enhancements, including performance features, are delivered through  function levels without waiting for a new release.  Function levels 100 and 500 activate the initial set of enhancements and capabilities in Db2  12. For migration from Db2 11, most new capabilities become available in Db2 12 only after  the activation of function level 500 or higher. In this IBMfi Redbooksfi publication, we focus  on the enhancements that are available in function levels 100 and 500. Db2 12 for z/OS continues the trend by focusing on further CPU savings and performance  improvement through innovations within Db2 and the synergy with IBM System zfi hardware  and software. While most of CPU reductions in analytical queries are built directly in Db2, other CPU and cost reductions are realized by using more real memory. Enhancements often  take effect after the REBIND in the case of static applications, while some enhancements  require user actions, such as activating function level, Data Definition Language (DDL)  updates, or providing more memory for Db2 to use. In this book, we describe the performance of Db2 12 for z/OS and the possible performance  affects of the most important functions when migrating from Db2 11. We include performance  measurements that were made in the Silicon Valley Laboratory and provide considerations  and high-level estimates. Results are likely to vary because the conditions and work differ.  For the purposes of this publication, we assume that you are somewhat familiar with Db2 12  for z/OS. For more information about the new functions, see  IBM DB2 12 for z/OS Technical  Overview , SG24-8383.  This book was produced by a team of performance specialists working around the world. Akiko Hoshikawa  is a Senior Technical Staff Member with the IBM Silicon Valley Lab, where  she leads the performance engineers for Db2 for z/OS development. She is responsible for  driving performance-initiated development in each Db2 release, working closely with Db2  developers. Her areas of expertise include system level performance tuning, Sysplex, and  XML. She has been involved with or written IBM Redbooks publications about Db2 for z/OS  Performance Topics since 1998. Bart Steegmans  is a Consulting Db2 Product Support Specialist from IBM Belgium, currently  working remotely for the Silicon Valley Laboratory in San Jose and providing technical  support for Db2 for z/OS performance problems. He has over 29 years of experience in Db2.  Before joining IBM in 1997, Bart worked as a Db2 system administrator at a banking and  insurance group. His areas of expertise include Db2 performance, database administration,  and backup and recovery. Bart is co-author of numerous IBM Redbooks publications about  Db2 for z/OS. ' Copyright IBM Corp. 2017. All rights reserved. xi