Decommission of Oracle Database

Decommission : A process to remove, Retire or making it inactive

Every organization has their own documents (SOP – Standard Operation Procedure) maintain for  removing or decommissioning the active  databases

I am presenting some general steps below.

1.      Requirement : Business/Customer to proceed for database decommissioning.

2.    Notifying Business/Customer / Application team that  “we are going to decommission the database at _ _ specific time” .

3.      Making the fresh backup :  Raise a ticket and assign it to Storage / Backup team and Co-ordinate with storage / backup team to take required backup. And to keep the backup for specified time(retention period).

4.      Make a list of parameter file, datafiles, controlfiles, redolog files.

-          Details of DB links using query: select * from dba_db_links;

-          List of all the data files using query: select * from dba_data_files;

-          List of log files using query: select * from v$logfile;

-          List of control files using query: select * from v$controlfile;

5.      Bring down the database and stop the listener.

6.      Take whole database backup and make sure backup is completed without any errors/warnings.

7.    Make sure Storage team has taken the backup as specified in the raised ticket against them and has set the retention period correctly. You can take a Signoff mail from Storage/Backup team in case it is required.

8.   Remove the monitoring jobs entry from crontab and also remove the monitoring jobs (if any) running from third party tool(s) in the database and comment out the entry from oratab file located in /etc directory.

9.   Mark in your database repository/inventory or your DB records , that this specific Database is going to Decom under this specific request at this specific time. (This will help to notify other DBA in your team).

10.   Startup the database in restrict mode and give drop database command.

                        SQL> startup restrict mount ;

                        SQL> drop database;

11.  Check if the instance is still running or not. Shutdown the instance if it is still running. Check and verify Alertlog for the list of files deleted.

12. Now remove the tracefiles, archive log files, dump files, old backup files and respective Database directories.

13.  Be careful before deleting the physical files. Crosscheck and verify before deleting these file.

14.  Now remove the backup “entry” through which backup was getting triggered.

15.  Notify the customer/Application team about the backup ticket , backup information such as retention period and location of backup.

Note : Retention Period may be varied based on your business needs and SLA

See Also :

- Dataguard Creation

- Pre-Check for Dataguard SwitchOver  

- Common Wait events in AWR and Solutions 

- Most Common Daily Datapump Scenarios