Evaluation interval

As Steven Jobs would often say:

There is one more thing ...

There is one more thing to say about rules. The Scheduler normally checks what to do at the start and the end of each and every job step. In many situations this may be good enough, but there are situations where something more is required. One example is where one step of a job not only depends on the status of a former step, but also on the row count of a table or on the time of day. If this is the case, it would be best if the job step starts running as soon as the condition becomes true; and not after we had to manually intervene to make the Scheduler evaluate the chain again. We can give the chain an evaluation interval to make the Scheduler not only check the status of the job when it starts the job (or a job_step ends), but also to repeat the evaluations on a timed basis. To run these repeated evaluations, we have to specify evaluation_interval. The evaluation interval is the way to make the Scheduler check...