According to the EJB 1.1 specifications and EJB 2.0 specifications, accessing the resource manager with the setEntityContext method is not allowed.

In the cases other than when you use a compound primary key as the primary key, you cannot use a user-defined type CMP field.

When using a Collection-type CMR field, or an Iterator of the Collection-type CMR field, you can access the CMR field and Iterator within the scope of the transaction when the CMR field is acquired. In the callTeam method of the following coding example, you must execute the getPlayers method that is the getter method of the CMR field, and all the operations using the succeeding Iterator in the same transaction (between [a] and [b]).

   public void callTeam() {
             ...
     //[a]
     Collection playersInTeam = team.getPlayers();
     Iterator i = playersInTeam.iterator();
     while (i.hasNext()) {
       LocalPlayer p = (LocalPlayer) i.next();
             ...
     }
     //[b]
   }

If you execute this coding example outside the transaction, the IllegalStateException exception will occur. To avoid this, specify the settings in CMT to execute within the transaction.

The following limitations are applicable for using the cascade-delete of CMR:

• When removing an Entity Bean with cascade-delete, you must specify the settings such that the client program that acts as the invocation source has not only the method permission of the remove method of the Bean that is removed first, but also the method permission of the remove method of the component interfaces of all the Beans that are the target of cascade-delete.
• Set up the transaction attribute of the remove method of the component interfaces of all the Beans that are the target of cascade-delete to Required.
• When multiple Beans are circulated in the relationship that specifies the cascade-delete, the execution of the remove method in all Beans that exist in the circulating relationship is not guaranteed.

When an interface and the abstract class are specified in the <prim-key-class> tag of the DD of a CMP Entity Bean, the error message KDJE42039-E is output during the deployment, and the deployment processing terminates with an error.

When you invoke an Entity Bean by using the home interface, you obtain the references by invoking the create method of the home interface; however, after completing the invocation of the Entity Bean, make sure that you release the references by invoking the remove method.

If you do not release the references, the memory on the J2EE server will be consumed.

You cannot specify an array as the argument type of the finder or select methods of EJB QL.