Manipulating the running chains

Chains are very powerful, but they also provide opportunities for errors that we have never seen before. One of the errors is forgetting (as system administrator) how one or more rules might cause our chain to get stalled. Another error is forgetting the evaluation interval for a chain that depends on something that is not a part of the chain. Think about a chain step that is supposed to run only when the current number of sessions is below a specified value. This status could be true when the previous step ends. If not, the number of sessions should be evaluated repeatedly until the step is allowed to start.

In the situation where we can see that the chain step is ready to run (because all the prerequisites are met), but we forgot to implement the evaluation interval, we can manually force the job to evaluate its rules using this piece of code:

begin
dbms_scheduler.evaluate_running_chain (job_name => 'a_running_job' );
end;
/

This piece of code will evaluate...