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So the Person.hbm.1.0.xml describes the mapping of files written with 1.0 to the current version of the person. This mapping wil change as the Person evolves and we still want to support read old project files. NHibernate has a rich feature-set to get the data from the old schema to the new objects such as formulas, custom sql, usertypes etc. Another advantage of this approach is that backwards compatibility is solved using stand NHibernate technology and not DS specific stuff.
What happens when an old project gets openened?
If deltashell Deltashell opens an old project it creates a session for that version of the DB to the current object model. After that all object objects are migrated to a new session with the current configuration. Then when the project is saved the database is in a new format.
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