What do you factor in when you are decommissioning an Oracle database or an IBM DB2?

Oracle Database/IBM DB2

How many times did you decommission a database? whether It could be an Oracle database or an IBM DB2 or MySQL server or Mongo or any other inhouse database. What factors do you take into account? Let's delve into these.

1. Backup the database.

   1. The first and foremost thing to do before touching any database server is to make a backup. A cold backup or a hot backup should be done.

   2. Once the backup is done, make sure that the entire metadata and user/schema data are there.

   3. Validate the backup and make sure, you are not missing anything.

2. Coordinate with other teams.

   1. Communicate with the application teams whose apps are hosted on the database.

   2. Communicate with the Firewall Team and make sure how and where the ports are being communicated and get the traffic details.

   3. Communicate with the Database team and see if there have been any transactions in the database in the last month.

   4. Communicate with the ETL Teams to make sure there are any ETL jobs using this database.

   5. Communication is crucial and coordination is vital for a successful database decommissioning.

3. Oracle Database Server.

   1. Gather all the details following,

      1. TNS Names.

      2. Oracle Listener.

      3. Oracle Cluster Details and Location.

      4. Monitoring on the Oracle Database and servers.

      5. Service names.

4. Oracle Database Schemas.

   1. Make sure the schemas are Obsolete.

   2. Purge any data that is not needed.

   3. Review the company's policies and archive the data for any future audit purposes.

   4. Review the backup policies, like after how many years can you delete the backups and so on.

5. Firewall ports.

   1. Make a list of all the firewall policies related to the database.

   2. Make a list of the database ports.

   3. Get the apps that are communicating with the database on these ports and notify their teams.

6. Mounts.

   1. Work with the storage team and make sure any related NAS mounts are unmounted.

   2. This applies to other types of mounts too.

7. Replication between the servers and data centers.

   1. Break the data guard between the primary database servers and the servers that are getting decommissioned.

   2. Thoroughly validate the above changes.

8. Open a Change Request for the prod Environment.

   1. For Production environments, open a Normal/Expedited/Emergency Change request. See which category of Change Request best suits you at that time.

   2. Fill in all the details and add the necessary approvers or group approvers.

   3. Take the Change Request to the approval committee.

   4. Once verified, submit the request.

9. Open an Incident or any other permissible request for the Non-Prod Environment.

   1. All Non-Production environment-related incidents should be coordinated with the concerned teams and depending upon the company's policies an incident or a request should be submitted.

   2. Validate the changes once the databases are decommissioned in the lower environments.

Oracle database.