Comparing BACKOUT performance

The backout recovery strategy is dramatically faster than most traditional forward recoveries as shown in the following figure. A backout recovery does not require image copies to perform a point-in-time recovery. Instead, it backs out the log records to undo or redo the changes that occurred between the selected point in time and the current point. This method returns the spaces and indexes to the required state without the overhead of restoring image copies, or rebuilding or restoring indexes.