I cannot give specific values to set them to, but you want to set them to the smallest value that works for your system. stmtheap is used for dynamic SQL compiling. If you have alot of dynamic SQL and it is not just basic select * from mytable stuff, then this obviously need increasing from the default. How big depends on your application. If it is too small, you will get a specific error about increasing this parameter. applheapsz is another one that depends on you application. The best way to tune this is to start at the default. If you get the error saying it is too small, increase it a little bit. Keep on doing this until the error stops.