Sorry for the delay.
The Rogers Sanders help me when I was studing for the certificaiton. I recomend this book! The good books also is from IBM. Did you see them?
Good luck in your exam!
I work for IBM DB2 L2 support team, DB2 Level 2 supporting involve 24x7 production database support, in-depth database systems analysis, review, and recommendations of client’s DB2 UDB environments including; system hardware and software optimization, database design and implementation, database maintenance, performance monitoring and tuning, high availability, disaster recovery, problem determination and database migrations.