In this post, you’ll learn more about the Oracle ErrorORA-00393: log string of thread string is needed for recovery of offline datafiles with the details on why you receive this error and the possible solution to fix it.
Oracle Error Description
ORA-00393: log string of thread string is needed for recovery of offline datafiles
Reason for the Error ORA-00393: log string of thread string is needed for recovery of offline datafiles
Log cannot be cleared because the redo in it is needed to recover offline datafiles. It has not been archived so there is no other copy available. If the log is cleared the tablespaces containing the files will have to be dropped.
How to fix the Error ORA-00393: log string of thread string is needed for recovery of offline datafiles ?
You can fix this error in Oracle by following the below steps
Archive the log then repeat the clear command. If archiving is not possible, and dropping the tablespaces is acceptible, then add the clause UNRECOVERABLE DATAFILE at the end of the clear command.