In Oracle Database, which SQL statement would you use from SQL Plus to create a backup copy of the control file at the database level?

Introduction / Context:
In Oracle Database, the control file is a small but critical file that stores metadata about the database structure, such as datafile locations and log history. Because it is essential for database recovery, administrators often create backups of the control file. This question focuses on the SQL statement used from tools such as SQL Plus to generate a backup copy of the control file.

Given Data / Assumptions:

• The environment is Oracle Database.
• We want to create a backup copy of the control file using a SQL statement.
• The action is typically performed from SQL Plus or a similar tool.
• Options mention ALTER DATABASE and other commands.
• RMAN, while powerful, is not the focus of this particular question.

Concept / Approach:
Oracle provides an ALTER DATABASE BACKUP CONTROLFILE command that can be used to back up the control file either to a binary file or to a trace file. The common form in SQL Plus is ALTER DATABASE BACKUP CONTROLFILE TO some file name or ALTER DATABASE BACKUP CONTROLFILE TO TRACE. This statement instructs the database to create a backup copy of the control file, which can later be used to recreate the control file if needed.

Step-by-Step Solution:
Step 1: Recall that the control file describes the physical structure of the Oracle database and must be protected. Step 2: Identify that the primary SQL command for backing up the control file at the database level is ALTER DATABASE BACKUP CONTROLFILE. Step 3: Note that the command requires a TO clause specifying a file name or TRACE, forming statements like ALTER DATABASE BACKUP CONTROLFILE TO filename. Step 4: Compare this syntax with the options and select the one that correctly matches the standard command format. Step 5: Confirm that the selected option is the appropriate SQL statement for this task and not an RMAN specific command.

Verification / Alternative check:
Oracle documentation and training materials show examples where administrators connect as a privileged user and issue ALTER DATABASE BACKUP CONTROLFILE TO TRACE or ALTER DATABASE BACKUP CONTROLFILE TO a file. This confirms that ALTER DATABASE BACKUP CONTROLFILE is the core clause and that the TO keyword specifies the destination, matching the correct option.

Why Other Options Are Wrong:
Option B, ALTER TABLESPACE BACKUP CONTROLFILE, is syntactically incorrect because control file backup is not a tablespace level operation. Option C mentions BACKUP CONTROLFILE USING RMAN, which sounds like a description of using RMAN but does not represent a valid SQL Plus statement. Option D, CREATE CONTROLFILE BACKUP, is not a valid Oracle SQL command. Option E, ALTER SYSTEM BACKUP CONTROLFILE TO ARCHIVELOG, blends keywords in a way that does not correspond to an actual control file backup command.

Common Pitfalls:
Administrators new to Oracle sometimes confuse RMAN commands with SQL Plus statements. While RMAN is the recommended tool for comprehensive backup strategies, exam questions often target the ALTER DATABASE BACKUP CONTROLFILE command. Another pitfall is mixing up control file backup with datafile or tablespace backup, which use different procedures and tools.

Final Answer:
From SQL Plus, the appropriate SQL statement to create a backup copy of the control file is ALTER DATABASE BACKUP CONTROLFILE TO filename;.