This is part 2 in the series that focuses on improving performance in Db2 Warehouse databases. The first part gave some background and discussed some basic concepts relevant to query optimization in the context of the Db2 column engine.
Part 2 : Identifying Costly Operations + Improving Joins
Playing with cardinality and selectivity on predicates is not a common trick, though Joe Geller, David Simpson and Tony Andrews demystify it so that you can start playing with its intricacies and give a boost to the Optimizer.
You have probably heard about Db2 12 Dynamic SQL plan stability already. However, before you decide to activate it, you should learn more first. This article is going to help you on your journey to stabilize your dynamic world.
One of the most common maintenance activities performed on a Db2 LUW database is running Runstats on tables and indexes. Accurate database statistics are vital for the Db2 Optimizer to produce the most optimal plans.
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"