ORA-01147: SYSTEM tablespace file string is offline

Oracle error

ORA-01147: SYSTEM tablespace file string is offline

Cause: A file belonging to the SYSTEM tablespace has been marked offline by the DBA. The database cannot be started until all SYSTEM tablespace files are online and openable.

Action: Bring the file online.

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ORA-01146: cannot start online backup - file string is already in backup

Oracle error

ORA-01146: cannot start online backup - file string is already in backup

Cause: When starting an online backup it was noticed that an online backup was already started for one of the data files.

Action: End the first backup before beginning another.

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ORA-01145: offline immediate disallowed unless media recovery enabled

Oracle error

ORA-01145: offline immediate disallowed unless media recovery enabled

Cause: ALTER TABLESPACE ... OFFLINE IMMEDIATE or ALTER DATABASE DATAFILE ... OFFLINE is only allowed if database is in ARCHIVELOG mode.

Action: Take tablespace offline normally or shutdown abort. Reconsider your backup strategy. You could do this if you were archiving your logs.

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