Let’s have a brief look at the MERGE statement implementation in DB2. As I am primarily working on DB2 for z/OS, I will focus on this flavor of DB2. However, if there are any significant differences in the MERGE implementation in DB2 LUW, please share them in comments.
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.
You know it. You’ve just successfully compiled, built, and bound your application program for DB2 for z/OS, but the execution fails with the SQL error code -805. What’s the problem? You’ve just got one of the most common errors each developer encounters. Let’s make a short overview of the -805.