To delete an instance:
- Go to the Cloud SQL Instances page in the Google Cloud Platform Console.
- Select an instance to delete by clicking the instance name.
- Click Delete.
- In the Delete database instance dialog box, click OK.
Delete the instance.
gcloud sql instances delete [INSTANCE_NAME]
After you delete an instance, it might still appear in your project with an "unknown" size but with a "Being deleted" status. This is normal and the instance should disappear completely after a brief period of time.
You cannot reuse an instance name for up to a week after you have deleted an instance.