Deactivation Between Incoming Data and Pre- and Post-Conditions

See Also

At run time, the Rules Engine makes a comparison between all incoming column values and the pre- and post-conditions of corrective UPDATE constraints. This comparison is made for each row event in which these constraints are involved.

If the column value and the pre-condition are mutually exclusive, the constraint need not be evaluated.

If the post-condition coincides with the column value, the constraint need not be evaluated either, because it will set the column to the value it already has. Of course this applies only if no other columns are changed by the constraint.

Here is an illustration of these two situations: