Scenario – your query is performing poorly. You see DB2 picked an access path that is less than optimal. First you make sure there are appropriate indexes. You look to see if the statement is written in a way that enables DB2 to use those indexes. Then you check the Filter Factors of the predicates.
Tracing is one of the strongest, but least understood, mechanisms available to you with DB2. It gives you the ability to lift up the hood, helping you determine what is going wrong and why. So don’t be lost for answers when DB2 hangs or consumes to many resources, start tracing. This presentation wi
April 2015 “Fun with SQL” Challenge 2
This month on the Content Committee blog we’ll be doing an online version of the “Fun with SQL” dojo. Each week we’ll present an SQL challenge and request the community to solve it.
Let’s speak today the database monitoring. DB2 is usually presented as a black box that stores and retrieves data for you. Usually we don’t care much about what is happening inside it. However as soon as a trouble arises, information about its internals becomes critical.
This article is a derivative work of the presentation “Sage Advice: 20 Invaluable DB2® LUW Performance Insights from Around the Globe” (IDUG North America 2014), plus enhancements and embellishments, of course!