Given below is a list of scenarios: 1. A user terminates his session abnormally. 2. The connection between the server and the client application terminates because of a network failure. 3. A schema…

Scenario 1 (abnormal session termination) and scenario 6 (instance shutdown from power failure) are handled automatically by Oracle background processes PMON and SMON respectively, requiring no DBA intervention.

Scenario 6 (power failure causing abnormal shutdown) is automatically handled by SMON performing instance recovery on the next startup, so it does not require DBA intervention.

Scenarios 3, 4, and 5 all require DBA intervention because they involve permanent logical or physical data loss. A dropped schema or tablespace cannot be automatically recovered and requires the DBA to use import/export, flashback, or media recovery. A corrupted hard disk with lost data files requires the DBA to perform media recovery from backups.

Scenarios 1 and 2 involve session and connection failures that are automatically resolved by the PMON background process cleaning up orphaned sessions and transactions, requiring no DBA action.