Explanation:
This answer contains correct syntax of command to switch the current log file: all scripts in RMAN run with the command RUN. Keyword SQL shows to RMAN that SQL command needs to be performed.
Incorrect Answers:
1: The syntax of command is incorrect, SQL keyword is missing in this statement.
2: The syntax of command is incorrect, all scripts in RMAN run with the command RUN, not START.
4: The syntax of command is incorrect, all scripts in RMAN run with the command RUN, not EXECUTE.
Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 585-591
Chapter 12: Overview of Backup and Recovery

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