File naming convention

# TODO explain the file naming convention # The following extract was inspired by the DBA documentation.

We recommend to use the following naming convention for migration files:

   [VERSION]-[MIGRATION]-[ORDER]-[TYPE].sql

- version : the release version

- migration : a free name for the migration

- order : a number used to order the files inside the migration

- type : ddl or dml, ddl if the file contains schema migration, dml if the file contains data migration.