The repository shall maintain bi-directional linkage between each AIP and its descriptive information

This is necessary to ensure that all AIPs can continue to be located and retrieved.

Descriptive metadata; unique identifier, persistent identifier or locator associated with the AIP; documented relationship between the AIP and its metadata; system documentation and technical architecture; process workflow documentation.

Repositories must implement procedures to establish and maintain relationships to associate descriptive information for each AIP, and should ensure that every AIP has some descriptive information associated with it and that all descriptive information must point to at least one AIP.

As mentioned in 4.5.1, the Bagging specifications also describes the minimum descriptive metadata needed for each bag, which includes the title and the unique identifier. A depositor can update bags as long as they have the bag name. Currently the UI allows search by title, object identifier, and Bag name. See also:  Definition of AIPs and Object Resource.

In addition, the files with which the Object Resource maintains relationships contain URI information as to where the stored copy is actually kept. See also the File Resource.

Links between data and descriptive information cannot be broken. Identified risks include bad actors and complete system failure. Both of these potential risks is unlikely, because APTrust maintains two up-to-date copies of the metadata database, one in Virginia and one in Oregon. Plus, this database is backed up multiple times per day in Virginia. See Also the Risk Management, Threats, and Mitigations page.

In the event that all copies of the metadata database are corrupted, essential metadata is stored along with the preservedobjects, and the database can be reconstructed based on this, though PREMIS event metadata would be lost. For a more in-depth description of the links between preserved materials and metadata, see Preservation and Storage.

In the event of the loss of the SQL database, APTrust could reconstruct the registry because of the tagged files for everything except PREMIS events (which we are encouraging institutions to record independently).