On DB2, the database configuration parameter APPLHEAPSZ determines the heap size. If you are using the Sun GlassFish or DataDirect database driver, set this parameter to at least 2048 for CMP. For more information, see http://publib.boulder.ibm.com/infocenter/db2luw/v8/index.jsp?topic=/com.ibm.db2.udb.doc/opt/tsbp2024.htm.