Some tuning suggestions for DB2 can be found at http://www-128.ibm.com/developerworks/db2/library/techarticle/dm-0404mcarthur/index.html

These include suggestions for tuning your SQL Statement so you do not need to rely on your DBA to do them. One improvement I have used in the past is the "SELECT … FOR READ ONLY" optimization. This will allow DB2 to speed up the statement execution in some cases.