Does Grails static 'mapping' property in Domain classes violate DRY? Let's take a look at the canonical domain class: class Book {      Long id      String title      String isbn      Date published      Author author      static mapping = {             id generator:'hilo', params:[table:'hi_value',column:'next_value',max_lo:100]      } } or: class Book { ...         static mapping = {             id( generator:'sequence', params:[sequence_name: "book_seq"] )     } } And let us say, continuing this thought, that I have my Grails application working with HSQLDB or MySQL, but the IT department says I must use a commercial software package (written by a large corp in Redwood Shores, Calif.). Does this change make my web application nobbled in development and test environments? MySQL supports autoincrement on a primary key column but does support sequence objects, for example. Is there a cleaner way to implement this sort of 'only when in production mode' without loading up the domain class?