Previously, I’ve talked about the new DB2 10 temporal tables and how they are great for data warehousing applications. To leverage the temporal tables and data warehousing applications within the DB2 for z/OS environment the system needs the proper DSNZPARM settings. Since everyone has too many systems, some organizations only review system DSNZPARMs during migrations, meaning that many of the new settings might not be set up or enabled. It’s a good idea to review the DSNZPARMs on a regular basis and get them set up to maximize the performance of your data warehousing application SQL by leveraging all the DB2 optimizer capabilities.
First, get a listing of the current DSNZPARMs for your data warehouse system’s settings. This can be done a number of different ways: through your performance monitor, through the JCL that creates the DSNZPARMs or through the IBM REXX exec of the DB2 stored procedure DSNWZP. This DSNWZP stored procedure routine is one of the many DB2 administration procedures and is set up during the system install.
The data warehouse DSNZPARMs affect the performance of the DB2 system and its applications in many different ways, from the DB2 optimizer’s access path choices to the number of parallel processes DB2 will perform during data retrieval. To make sure that all DB2’s performance features and functions are available to improve performance I've created an alphabetic list of DB2 data warehouse DSNZPARMs. Making sure these data warehouse DSNZPARMs are enabled and adjusted for your system will help your application fully exploit DB2 and get the best performance possible for your data warehouse.