Whenever a performance problem arises, the database takes the blame, but is that really true? This article will provide a hand's on, step by step approach to determine where the problem is. "Guilty Until Proven Innocent"
By now, most DB2 for LUW users have probably heard about the release of DB2 11.1 that became available in June of this year. In this article I’d like to provide more information on some performance optimizations in DB2 11.1 that will benefit queries accessing both row and column-organized tables.
There has been quite a bit of attention paid to the access path stability features of DB2 for z/OS since they first appeared in DB2 9. Enhancements have followed in each subsequent release. This article will discuss these features.
With each new release, DB2 is getting smarter and smarter. However, DB2 is not yet clairvoyant enough to understand the intentions of all queries and turn them into optimal forms. What’s the bottom line? Do you need to worry about how you code? The answer is yes, but not as much as in the past.
We use Explain to find out the access path for a query. Jim Dee, from BMC shows you how you can compare the access path with previous versions of the query or package – comparing the estimated costs, and identifying those that have changed with a rebind.