### Step-by-step Guide to Change the Log Operation Mode in Three Steps
By default, Oracle databases operate in **non-archived mode**. However, this mode does not prevent data loss issues caused by physical damage. Therefore, database administrators may need to switch the log operation mode from non-archived mode to **archived mode**. In fact, this conversion can be accomplished in just three simple steps. However, before performing these operations, it is important to note that all of the following operations require the user to have database administrator privileges—only users with **SYSDBA** or **SYSOPER** roles can execute these operations.
### Specific Steps to Change the Log Operation Mode:
#### Step 1: Determine the Current Log Operation Mode
Before changing the current log operation mode, the database administrator must first confirm the current mode. This can be done by querying the dynamic performance views to determine the current log operation mode. For example, you can use the following statement to retrieve the required information. Dynamic performance views store a lot of runtime information about the database, and from them, the database administrator can obtain many useful details. To understand the current log operation mode of the database, you can query the database's dynamic performance views.
For instance, you can use the following SQL query:
```sql
SELECT log_mode FROM v$database;
```
This will return either **ARCHIVELOG** or **NOARCHIVELOG**, indicating whether the database is currently operating in archived or non-archived mode.
---
#### Step 2: Shut Down the Database
Once the current mode is confirmed, if it is necessary to switch to **ARCHIVELOG** mode, the next step is to shut down the database cleanly. Use the following command to shut down the database:
```sql
SHUTDOWN IMMEDIATE;
```
This ensures that all active transactions are completed and no data is lost during the shutdown process.
---
#### Step 3: Enable ARCHIVELOG Mode and Restart the Database
After shutting down the database, start it in **mount** mode and enable ARCHIVELOG mode. Use the following commands:
```sql
STARTUP MOUNT;
ALTER DATABASE ARCHIVELOG;
ALTER DATABASE OPEN;
```
These commands start the database in mount mode, enable ARCHIVELOG mode, and then open the database for normal operation.
---
### Important Notes:
1. **Privileges**: Only users with **SYSDBA** or **SYSOPER** privileges can perform these operations.
2. **Backup**: Before making any changes to the log operation mode, it is highly recommended to back up the database to avoid potential data loss.
3. **Confirmation**: After enabling ARCHIVELOG mode, you can confirm the change by re-running the query:
```sql
SELECT log_mode FROM v$database;
```
The result should now show **ARCHIVELOG**.
By following these three steps, the database administrator can successfully switch the log operation mode from non-archived to archived mode, enhancing data protection against physical damage.