Top 2 DB2 WTF's to be aware of during migration

I return back after a really long time. I got tied up with another of those weary DB2 to Oracle migration projects. Sometimes one wonders if there is some sanity in other RDBMS implementations.

When doing a migration exercise, be on the look out of the following two WTF's of DB2:

• Empty strings - basically allows you to pass in a '' into a column defined as a NOT NULL.
• Undefined default values - don't even bother understanding what this is all about. It basically allows one to define a column as NOT NULL and ascribe an UNDEFINED default value (enter the empty string).

And, mind you, developers love to consume these features!