Frequent commits are widely understood to negatively impact performance. Thus, committing inside a loop (even when only executed conditionally once every n iterations) is highly likely to cause unwanted performance impacts.
Further, in general use ``++COMMIT++`` should only be used at the end of a transaction. Code that is not structured to have one transaction per loop iteration could yield unexpected results if ``++COMMIT++`` is nonetheless used inside the loop. Code that _is_ structured to have one transaction per loop iteration should probably be reconsidered.
Note that when dealing with very large data sets, a ``++COMMIT++`` may be required every n iterations, but the goal should be to avoid ``++COMMIT++``s inside loops.
