Database updates and queries occur throughout the workflow. Descriptive, identifying, structural, technical, administrative and event metadata are recorded for each object.

Data model

The AIP structure of Rosetta corresponds to the PREMIS data model. It is a logical AIP.

IE

An IE represents an object to be preserved. An IE can have 1-n representations, each of which consists of 1-n files. Precisely one of the representations must be the PRESERVATION MASTER. Additional representations can be defined.

The METS file contains:

• The descriptive, technical, structural and administrative metadata for an IE
• Information about representations, and references to the storage paths of files belonging to the relevant representation
• The reference to the internal-system ID under which the XML file is stored together with the catalogue metadata.

The IE, the representations and every file are each assigned a unique, internal-system identifier.

Representation

Representations describe different manifestations of an object, such as an access copy. A representation can have 1-n files.

Each IE contains at least one representation, the PRESERVATION MASTER.

The PRESERVATION MASTER contains the unchanged original files. There must always be a preservation master. There may not be more than one preservation master.

The PRE-INGEST MODIFIED MASTER contains a copy of the original files that has been created before deposit, and modified by the librarians. Modifications are changes to the original files, such as creating an order or adding a title page. A pre-ingest modified preservation master is optional. There may be no more than one pre-ingest modified master in an AIP version.

The MODIFIED MASTER contains a modified copy of the original files. These modifications are created by file format migration, for example. A modified master is optional. There may be no more than one modified preservation master in an AIP version.

The DERIVATIVE COPY contains the access copy. The derivative copy is optional. There may be several derivative copies.

Additional representations can be defined.

File

The METS structural map describes the relationships of files within a representation.

Metadata

Each IE contains descriptive, technical, structural, legal, administrative and preservation metadata. Metadata may be delivered together with the transfer information packages, or may be added to the SIP during ingest. In addition, the Rosetta digital preservation software creates metadata.

Functions of the various packages

A submission application creates Rosetta-compliant pre-ingest SIPs from various transfer information packages, and transfers them to Rosetta during the second step. The two processes – IE creation and deposit – can be carried out separately, enabling the member of staff to check the created packages and to enrich them with additional metadata.

For the creation of pre-ingest SIPs, the submission application expects defined transfer information packages.

After deposit, the pre-ingest SIPs become post-ingest SIPs, which are enriched with additional metadata by the system. The transformation process is complete when a package has been transferred to permanent archival storage and successfully deposited there.

The transformation process of the different package structures is documented in detail in the graphic Transforming SIPs into AIPs.