Top 10 Performance Tuning Tips for IBM Db2

Performance is a critical aspect of any database management system, and IBM Db2 is no exception. As organizations deal with ever-increasing data volumes and complex workloads, it is crucial that Db2 environments are fine-tuned to ensure optimal performance, responsiveness, and scalability. In this multi-part blog post, I will examine the top ten performance tuning tips for assuring optimal IBM Db2 applications and systems.

Whether you are an experienced database administrator or just starting your journey with Db2, these performance tuning tips will provide some practical strategies and techniques to enhance the efficiency and speed of your Db2 deployments. This series of posts will cover a range of topics, including query optimization, database design, indexing strategies, memory configuration, I/O optimization, and more. 

By following these Db2 performance tips, you can significantly improve query response times, optimize resource utilization, and ensure the smooth operation of your Db2 environment. Whether you are dealing with transactional workloads, analytical queries, or a combination of both, the tips presented here will equip you with the knowledge and techniques to tackle performance bottlenecks and fine-tune Db2 to meet your specific needs.

Whether you are looking to optimize existing Db2 deployments or planning for a new implementation, this blog post will serve as a valuable resource to guide your performance tuning efforts. So, let's dive into the top ten performance tuning tips for IBM Db2 and discover how you can unlock the full potential of your database system.

Here's an outline for the upcoming posts in this series on "Top 10 Performance Tuning Tips for IBM Db2":

  Tip 1: Analyze Query Execution Plans

  Tip 2: Optimize Database Design

  Tip 3: Efficient Indexing Strategies

  Tip 4: Effective Memory Configuration

  Tip 5: Workload Management and Query Optimization

  Tip 6: Monitoring and Performance Metrics

  Tip 7: Configuration Parameters and Tuning

  Tip 8: I/O Optimization

  Tip 9: Regular Maintenance and Housekeeping

  Tip 10: Stay Up to Date 

So be sure to keep tuning in to the Db2 Portal blog as we publish these Top 10 Performance Tips over the course of the next few weeks.

And be sure to share your own performance and tuning thoughts here... or on any of the subsequent posts in this series.

How Many Temporal Tables Does Your Site Have?

Sometimes it can be difficult to remember where information is stored in the Db2 Catalog. Usually, with a little rumination and a little review of Appendix A of the IBM Db2 SQL Reference manual (SC27-8859), you can come up with a solution.

For example, I was talking to some DBAs who were trying to remember if they had ever created any business-time temporal tables. A comment was made that we could surely find that in the Db2 Catalog and the conversation moved along... but then I thought, hmmm, let me see what I can do about coming up with a catalog query.

The first step was to think about where this information might be found, which took me to SYSTABLES. A good first thought, but no, it isn't there. So I thought, how about SYSCOLUMNS? And lo' and behold, there was the answer.

The columns identified as the start and end date/time for the temporal range are documented in SYSCOLUMNS in the PERIOD column. PERIOD is defined as a CHAR(1) column and it contains one of the following values for every column defined for each table:

Value	Meaning
B	Column is the start of period BUSINESS_TIME
C	Column is the end of period BUSINESS_TIME with     an exclusive endpoint
I	Column is the end of period BUSINESS_TIME with     an inclusive endpoint
S	Column is the start of period SYSTEM_TIME
T	Column is the end of period SYSTEM_TIME
blank	Column is not used as either the start or the end of     a period

So using this information, here is a query that will show information about all of the business-time temporal tables you have created:

SELECT SUBSTR(TBCREATOR,1,8) || '.' || SUBSTR(TBNAME,1,30) 
       AS TABLENAME,
       SUBSTR(NAME,1,40) AS COLUMNNAME, 
       COLNO, 
       PERIOD
FROM   SYSIBM.SYSCOLUMNS
WHERE  PERIOD IN ('B', 'C', 'I')
ORDER BY TABLENAME, PERIOD, COLUMNNAME;

If you want to find the system-time temporal tables, just swap out the WHERE clause with this one:

  WHERE PERIOD IN ('S', 'T')  

By becoming adept at querying the Db2 Catalog tables you can find out just about everything you want to know about the databases and objects defined in your Db2 subsystems!