I agree that avoiding schema doesn't solve the problem. My point is that your schema exists in your code one way or another (explicitly or implicitly), and even

I agree that avoiding schema doesn't solve the problem. My point is that your schema exists in your code one way or another (explicitly or implicitly), and even without a database schema, you still need to either handle the schema differences in your code, or you need to migrate your data into the new schema in some way or another. The best use of schema-less data storage I've heard of is Craigslist of MongoDB for their archives. Apparently migrations on their MySQL servers was taking way too long, and switching that system to Mongo made a lot of sense and apparently has worked out pretty well. In the end it's about understanding the use of the right tool for the right job.