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# CDM Versioning

The [[CdmLibrary]] is supposed to support versioning of CDM data. The simplest approach to create a new version would be to copy every _current_ object in the CDM and leave the old ones untouched. This would effectively mean a copy of the entire database for every single version, because nearly all objects in the CDM are related to each other in some ways. Obviously this is not a scalable solution. We will have to address versioning therefore on the atomic domain objects. The following graphic shows the complexity and dependencies of CDM objects:

![](version_complex_objects)

## Version In Time

For a single point in time a consistent complex object can be assembled based on the multiple versions stored. The following example shows different versions of a taxon made up of a name that in turn is based on an author.