Best practice for managing data-model changes in a released system

Question

I am about to embark on the development of a web application project.

I'd like to get something up early and often for early adopters to play with and feedback.

But I envisage the data model changing as the project progresses and my understanding of the system improves.

How should I manage the dilemma of updating the data model appropriately and preventing data loss for early adopters? Should I simply put up a big warning saying "user beware", or should I put in the effort to create migration scripts?

Answer 1

What platform are you using? Ruby on Rails gives you migration scripts as part of the package. If you're in Java-land, you might want to check out migrate4j.

In the end, I'd suggest doing both things: Warn your users that they're using alpha software, and employ migration scripts with the intent of preserving their data whenever you can (lest they become peeved and lose interest).

Answer 2

Scott Ambler has written some nice stuff about agile databases. There's a book and a website.