Rails use a UTC time stamp as migration version by default. Although most examples in books have simple number based system for managing migration versions, there isn't much information about version type configuration. By default, a migration file(>=Rail 2.0) name look similar to:
We can turn this off and use numeric prefixes by adding this in
New generated file name will look like:
But bare in mind, if the Rails project is getting large and a few developers are working on same project, it's likely that two developers generate same version of migration (e.g. 003). Using time stamp is introduced since Rail 2.0 to avoid such problem. So... better keep the default setting!