[abhchand]

This was my same thought. Really impressive as an exercise to develop this yourself, but this is core functionality of a lot of ORMS. Rails' ActiveRecord is kind of the shining example of this, with it's `schema.rb` versioning file

[akie]

This is more meant as something that supplements migrations, as a “time machine” of your database so to speak. You would run it before you do any kind of potentially destructive operation on your database, such as running or rolling back a migration. Not all migrations are reversible (for example, migrations that drop columns), so you cannot easily go back to before you ran that migration. It’s also convenient when you check out an older version of your code - you can just restore the database as it was at that point in time. You could run a command in a git hook to enforce saving a new version when you tag a new release for example. In any case, it makes your database less of a black box, and it basically becomes ok to destroy it - because you can so easily make a new snapshot and go back to how it was before.

[matsemann]

I think this is for data too, not just schemas.