Oracle Solution for Error ora-01624

ORA-01624: log string needed for crash recovery of instance string (thread string)

What triggered the Error:

A log cannot be dropped or cleared until the thread's checkpoint has advanced out of the log.

What should we do to fix it:

If the database is not open, then open it. Crash recovery will advance the checkpoint. If the database is open force a global checkpoint. If the log is corrupted so that the database cannot be opened, it may be necessary to do incomplete recovery until cancel at this log.