You can specify an optional join condition in target activities. The value of the join condition is a boolean expression. If a join condition is not specified, the join condition is the disjunction (that is, a logical OR operation) of the link status of all incoming links of this activity.

Oracle BPEL Designer does not provide design support for adding join conditions. To add a join condition, you must manually add the condition to the .bpel file in Source view in Oracle BPEL Designer.

The following provides an example of a join condition.

<flow>
   <links>
      <link name="linkStatus2"/>
   </links>
   <empty name="E2">
      <sources>
         <source linkName="linkStatus2">
            <transitionCondition>false()</transitionCondition>
         </source>
      </sources>
   </empty>
   <empty name="E2">
      <targets> 
         <joinCondition>bpws:getLinkStatus('linkStatus2')=true()</joinCondition>
         <target linkName="linkStatus2"/>
      </targets>
   </empty>
</flow>