It has always been very important to understand when any changes in your database's configuration are made – some changes can have huge consequences. This article presents a methodology for monitoring your databases' configuration and detecting when changes have been made.
Tuning of SQL queries requires understanding why DB2 chose a particular access path and determining whether or not that access path should perform as expected. The key to this is understanding what filter factors are, how they are used by the Optimizer and how to get DB2 to better estimate them,
Let’s start this discussion candidly – I am a big fan of the FETCH FIRST n ROWS ONLY clause coded in a SQL statement. That assertion will require some clarification, since there are some valid use cases, and others that make little sense. Regardless, I will try not to over-complicate the discussion.
In February 2016 the DB2 12 Editorial Committee was formed, comprised of volunteers from IDUG’s worldwide community of DB2 users and consultants. This White Paper contains their findings, including practical experiences and independent evaluations of the new features.