If I am hosting a hierarchical CMDI metadata collection, do I need to offer all records over OAI-PMH or only the root nodes?

Short answer: as indicated in the

Open Archives Initiative Protocol for Metadata Harvesting

See: http://en.wikipedia.org/wiki/Open_Archives_Initiative_Protocol_for_Metadata_Harvesting

protocol, you need to offer all records. There is no automatic harvesting of any of the

Component Metadata Infrastructure

See: http://www.clarin.eu/cmdi

child nodes.

 

Long answer: in the case of our toy example hierarchy (http://www.clarin.eu/faq/3454)

 

You would need to provide the following files over OAI-PMH:

 

 

Providing collection_root.cmdi (or even collection_olac.cmdi and collection_lrt_inventory.cmdi) is not enough, as all OAI harvesters are protocol-agnostic and thus do not know about CMDI’s hierarchy building! CMDI-consuming applications, such as the

Virtual Language Observatory

See: http://www.clarin.eu/vlo

, also need the physical files locally.