Activate and deactivate archivelog mode in Oracle

REQUIREMENT: 

During the client copy activity, a lot of archive log files will be created due to lots of changes are being done to the target system.

1. Hence it is required to run the Archive log backup frequently. If not, there is a fair chance that Archive directory becomes 100%.
2. We can get rid of the issue by extending the disk space and by scheduling the Archive log backup periodically (for example, every 30 minutes).
3. But many prefer it to disable the archiving (which means- run the database in NOARCHIVELOG mode) before the client copy, due to the disk space limitations.
4. Turning off the archiving avoids archive stuck situations as no logs are created, also the client copy will be faster.

Below are the steps to be followed to disable the ARCHIVELOG mode.

[1] Check the current status of ARCHIVE LOG mode

Issue the below command from Oracle SQL prompt

SQL > select  log_mode from v$database;

LOG_MODE

------------------

ARCHIVE LOG

The result from the above command is: Database is in 'ARCHIVE LOG' mode.

Our aim is to disable the archive log mode.

[2] shutdown the oracle database with the below command

SQL > shutdown immediate;

[3] Database should be in 'MOUNT' status (Command is as below)

SQL> startup mount

[4] Now we are good to issue the below command to disable the ARCHIVE LOG mode

SQL > alter database noarchivelog;

[5] Final command is to open the database

SQL > alter database open;

NOTES:

• ARCHIVE LOG mode status is changed now and the status can be checked with the command from the step [1]. 
• Please make sure that re-enable the archiving after the client copy is finished. Follow the same steps except replacing the command in step [4] with alter database archivelog;