| ERROR | datafile string checkpoint string is ahead of space bitmap datafile string checkpoint string |
| CAUSE | When checkpointing the datafile containing the space bitmaps for the datafile being backed up in order to use Unused Block Optimization, the checkpoint of the datafile containing the space bitmaps did not advance. |
| ACTION | Examine the trace and alert files for possible causes. Fix underlying problem to use Unused Block Optimization for datafiles backup. |