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These training archives may be out of date, but have been retained and kept available for the community's benefit in reviewing previous sessions.

Current training documentation can be found here: Training

Learning Outcomes

  • Understand the main differences between Fedora 3 and Fedora 4
  • Understand the considerations necessary for migrating from Fedora 3 to Fedora 4
  • Explore new possibilities for enhancing data in Fedora 4

Differences Between Fedora 3 and Fedora 4

XML Objects vs. Nodes

Fedora 3Fedora 4
FOXML objectsModeShape nodes (still referred to as objects)
Inline and managed XMLRDF properties*

*XML Datastreams are still supported

Flat Filesystem vs. Hierarchy

Fedora 3Fedora 4
Objects and Datastreams stored in flat directoriesObjects and datastreams stored in a hierarchical filesystem

PIDs vs. Path

Fedora 3Fedora 4
Objects have Persistent Identifiers (PIDs)Objects have a path (including a UUID) based on their location in the file system hierarchy
 Objects can also have other identifiers (DOIs, Handles, PIDs, etc.)

Migration Considerations

To Ingest or Federate?

  • In addition to normal ingest, Fedora 4 supports federation over content in a existing file system.
  • Federating over Fedora 3 content is possible, but the connector would need to be updated and modified to suit a particular use case.
  • Federation also does not provide any opportunities for data enhancement, which is an important consideration.


  • What kind of security does your Fedora 3 repository use?
  • Many Fedora 3 repositories use XACML security; this is supported in Fedora 4.
  • However, it would be prudent to test your specific XACML policies within the context of Fedora 4.
    • While XACML in general is supported, broad testing of existing policies is recommended.


  • Does your Fedora 3 repository use versioning?
  • What versions do you want to preserve? Object or datastream level?
  • How should version dates be handled? Will you use the system modified date, or a special date property?

Content Models

  • How are content models used in your Fedora 3 repository?
    • Do they have any logic built into them, or is that handled at a higher application level (e.g. Islandora, Hydra)?
  • Are there opportunities for building common content models that could be shared between Fedora implementations?
    • E.g. Islandora content models that can also be recognized by Hydra.


  • Does your Fedora 3 repository make use of disseminators?
  • What are they used for? XSLT transformations? Something else?
  • How can we support the existing disseminator use cases in Fedora 4 without re-creating disseminators?

Other Considerations

  • Have we left anything out?
  • What else needs to be considered when planning a migration?


Taking Advantage of Properties

  • Converting Inline XML and/or XML Datastreams (e.g. RELS-EXT, RELS-INT) to RDF properties.
    • Inline XML is no longer supported.
  • Lightweight compared to XML.
  • New possibilities for complex queries that extend beyond the limits of the repository.
    • Linked data relationships can be exposed via a standardized REST-API
    • Web applications can take advantaged of these standardized representations.
    • Data can be shared and manipulated in new and interesting ways.

Enhancing Your Metadata

  • XML metadata datastreams are still supported, but there are new opportunities to explore!
  • XML metadata can be converted into RDF metadata using an RDF-based schema.
  • RDF metadata is easier to query and share.
  • Take advantage of linked data by pointing to authority URIs.
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