In this post, you’ll learn more about the Oracle ErrorORA-01209: data file is from before the last RESETLOGS with the details on why you receive this error and the possible solution to fix it.
Oracle Error Description
ORA-01209: data file is from before the last RESETLOGS
Reason for the Error ORA-01209: data file is from before the last RESETLOGS
The reset log data in the file header does not match the control file. If the database is closed or the file is offline, the backup is old because it was taken before the last ALTER DATABASE OPEN RESETLOGS command. If opening a database that is open already by another instance, or if another instance just brought this file online, the file accessed by this instance is probably a different version. Otherwise, a backup of the file probably was restored while the file was in use.
How to fix the Error ORA-01209: data file is from before the last RESETLOGS ?
You can fix this error in Oracle by following the below steps
Make the correct file available to the database. Then, either open the database, or execute ALTER SYSTEM CHECK DATAFILES.