One of us once worked in a place where a system administrator saw some *.log files in several directories and decided that since they were just log files, they could be deleted:
$ rm *.log
The log files that were removed were all of our online redo log files for the database. Oops! Big mistake—we had to perform an incomplete database recovery to get our database back online.
Incomplete database recovery means that you cannot recover all committed transactions. Incomplete means that you do not apply all redo to restore to the point of the last committed transaction that occurred in your database. In other words, you are restoring and recovering to a point in time in the past. For this reason, incomplete ...