The Great Wall of Maintenance

Originally Posted 9/23/2104

1411458148The Great Wall. A symbol of strength that has lasted for centuries. But how did it last? Was it the engineering that allowed it to weather the test of time? Was it the native rock that allowed it to survive? Was it the loving care of individuals that allowed it to stay intact?

I never really thought about these questions before I visited the Mutianyu section of the Great Wall on a recent trip to Beijing. It was my first time to Beijing and I knew that a trip to the wall was a must. I had not had time to research before my trip (which is not like me), so I was not sure what to expect. I thought I would be impressed by the engineering, or the scenery. Instead, as I walked the wall and saw all the new bricks replacing the original granite, I started to think about the power of maintenance.

What does this have to do with the modern DBA? It is another reminder that all things need maintenance. As the pace of IT increases, and Database Administrators focus more and more on delivering systems, we need to remember that long term success only comes with the care and feeding of what has been entrusted to us. As we deliver database systems we need to ensure that maintenance plans are part of the deliverable. All systems need to have regular index and statistical maintenance to ensure that the database engine has the information it needs to generate efficient plans and minimize the resources needed to execute them.

And we can’t deliver these maintenance plans in a set it and forget it mind set. The Mutianyu section of the Great Wall follows the ridge line of a mountain chain. It was originally built using the granite quarried near by. But, along the way they switched from using the granite to bricks made from what appeared to be concrete. Why did they make the switch? I don’t know for sure. But I know that if they continued to repair the wall using the mountain itself, they would eventually erode the foundation on which the wall was built. Similarly, if you put plans in place and do not monitor them the ever shifting environment of IT can make the foundation of your maintenance unsound.

To ensure that you avoid this problem, you need to monitor how long your maintenance plans are taking. Are they still completing in your allotted windows? Also, you need to check in with your customers periodically to ensure that the windows for maintenance haven’t shifted or, as more likely the case, shrunk. Also, how effective is your maintenance? Do you track run times for important quires throughout the day? If not, this information can help you decide if maintenance can be run less frequently if your windows do shrink.

Spend the time to build an effective maintenance strategy and a plan to monitor your maintenance and who knows, your system may still be running in 600 years. You’ll be out of support, but it might just still be running.

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