Fractional Architect
In the last post about deployment strategies, I promised I wouldn’t leave the topic of database challenges when we have to support various, parallel application versions. It is the perfect time to face it. I will walk you through several real-world scenarios I have encountered frequently in my past projects.
Before we look at the scenarios, let's first outline the common problems developers face when trying to maintain database compatibility across parallel versions:
Query compatibility. How do you ensure that older application versions can still effectively query the database after schema changes?
With this in mind, you must always prepare the entire migration plan for the change. You know how it goes - someone says, “We will figure it out as we go,” and suddenly you are in hot water. Customers are locked out, nothing works right, and you are sweating bullets. Not fun, right?
Now you have got a game plan in your pocket. Sure, life loves to throw curveballs. Your plan might need to twist and turn a bit - that is normal. But here is the cool part: you are not going in blind. You have thought through the various scenarios before they happen.
