Today, March 31, 2021, is World Backup Day. With that in mind, let me use today’s blog post to remind you of the importance of backing up your databases… and testing your backups!
Of all the DBA roles and responsibilities the recoverability of your organization’s data is perhaps the most important. This means that you should understand the recovery requirements of all the databases you manage. This can only be established by communicating with the end users of the data stored in the database.
As you work with the consumers of the data to map out your backup plans, you will need to balance two competing demands: the need to take image copy backups frequently enough to assure reasonable recovery time, and the need to not interrupt daily business. The DBA must be capable of balancing these two objectives based on usage criteria and the capabilities of the DBMS.
Of course, some data may not need to be backed up at all… but this is rare. Data of this type is recreated or loaded to the database periodically. For example, if the data gets refreshed from another source you may not really need to worry about backing it up. Of course, you should always verify such things before just moving ahead without a backup plan!
To plan and establish a viable backup strategy and schedule, you must analyze your databases and data to determine their nature and value to the business. To do so, answer the following questions for each database object.
- How much daily activity occurs against the data?
- How often does the data change?
- How critical is the data to the business?
- Can the data be recreated easily?
- What kind of access do the users need? Is 24/7 access required?
- What is the cost of not having the data available during a recovery? What is the dollar value associated with each minute of downtime?
You can use the answers to these questions to work out a reasonable backup strategy and implement it.
But before ending this post, I want to circle back to a comment I made near the beginning of the post. And that is “test your backups before you need them for a production recovery!” The last thing you want to happen is to have made the wrong (or invalid) backups only to need them to recover from a problem. So put in place a strategy for testing your backups periodically… or risk having them not work properly when you need them!
I can think of no better high-level advice on World Backup Day than what I’ve outlined here… take some time, evaluate your DBA priorities, and be sure to review your database backup and recovery plans… you’ll be glad you did should the unthinkable occur!