Transaction redo using skip element for object

The use of a skip element when redoing transactions, so as to avoid tracking dependencies between transactions assigned to different threads for parallel processing. When the second thread comes to a second task in the course of redoing a second transaction, if a first task that is mooted by the second task is not already performed, the second thread inserts a skip element associated with the object to be operated upon by the particular task, instead of actually performing the particular task upon the object. When the first thread later comes to the first task in the course of redoing a first transaction, the first thread encounters the skip element associated with the object. Accordingly, instead of performing the dependee task, the first thread skips the dependee task and perhaps removes the skip element. The result is the same regardless of whether the first or second task is redone first.