Book Image

IBM DB2 9.7 Advanced Administration Cookbook

Book Image

IBM DB2 9.7 Advanced Administration Cookbook

Overview of this book

IBM DB2 LUW is a leading relational database system developed by IBM. 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. With lots of new features, DB2 9.7 delivers one the best relational database systems in the market. IBM DB2 9.7 Advanced Administration Cookbook covers all the latest features with instance creation, setup, and administration of multi-partitioned database. This practical cookbook provides step-by-step instructions to build and configure powerful databases, with scalability, safety and reliability features, using industry standard best practices. This book will walk you through all the important aspects of administration. You will learn to set up production capable environments with multi-partitioned databases and make the best use of hardware resources for maximum performance. With this guide you can master the different ways to implement strong databases with a High Availability architecture.
Table of Contents (21 chapters)
IBM DB2 9.7 Advanced Administration Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Default automatic statistics collection


Auto runstats uses distribution and sampled detailed indexes all when no profile is set for a table.

Collecting statistics using a statistics profile

The SET PROFILE clause creates a statistics profile for a table, so later stats collection will use it. If you use automatic maintenance on the database, it will also use this profile for the stats collection:

[db2instp@nodedb21 ~]$ db2 "RUNSTATS ON TABLE POSP.DAILY_SALES
>      ON ALL COLUMNS AND INDEXES ALL
>      ALLOW WRITE ACCESS
>      TABLESAMPLE BERNOULLI ( 10 )
>      SET PROFILE
>      UTIL_IMPACT_PRIORITY 10"

Background stats collecting (asynchronous)

Background stats collecting (or automatic runstats) is enabled by default when creating a database. The database configuration parameter is AUTO_RUNSTATS. You can change it directly or through the control center. The characteristics for automatic runstats are as follows:

  • Performed using throttled runstats, adjusts its priority automatically...