Table of Contents

  1. Introduction
  2. Namespaces Used
  3. Breakdown
    1. Base Triples
    2. Dublin Core Triples
    3. RELS-EXT Triples
    4. Content Model Architecture Triples
    5. Datastream Triples
  4. Calculating Triples/Object

  1. Introduction

    The resource index stores system and user-controlled metadata about each object in the repository in the form of RDF triples. The number and type of triples stored depends on the content of the object. This document describes the triples that may exist in the resource index for a given object.

  2. Namespaces Used

    For brevity, the URIs used in this document are shown in abbreviated form. To determine the unabbreviated form of any such URI, replace the Prefix with the associated Namespace URI below.

    Prefix Namespace URI
    dc: http://purl.org/dc/elements/1.1/
    fedora-model: info:fedora/fedora-system:def/model#
    fedora-view: info:fedora/fedora-system:def/view#
    rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns#

  3. Breakdown

    1. Base Triples



      The following triples will exist for any object, irrespective of its datastream content.

      Note: The predicate rdf:type is deprecated and will be removed in a future version.

      SubjectPredicateObjectCardinality
      info:fedora/$PIDrdf:typefedora-model:FedoraObject or fedora-model:FedoraBMechObject or fedora-model:FedoraBDefObject or fedora-model:FedoraCModelObjectExactly One
      info:fedora/$PIDfedora-model:createdDate(date created in UTC)Exactly One
      info:fedora/$PIDfedora-view:lastModifiedDate(date modified in UTC)Exactly One
      info:fedora/$PIDfedora-model:statefedora-model:Active or fedora-model:Inactive or fedora-model:DeletedExactly One
      info:fedora/$PIDfedora-model:owner(any string)Exactly One
      info:fedora/$PIDfedora-model:label(any string)Exactly One

    2. Dublin Core Triples



      Every object in Fedora has a Dublin Core ("DC") datastream. The following triples are derived from its content, which may consist of any number of each of the 15 unqualified dublin core elements. If unprovided at ingest, the DC datastream will be automatically created with minimal information (a dc:title and a dc:identifier).

      SubjectPredicateObjectCardinality
      info:fedora/$PIDdc:title(any string)One or More
      info:fedora/$PIDdc:identifier(any string)Once or More
      info:fedora/$PID(any other dc predicate)(any string)Zero or More

    3. RELS-EXT Triples



      Note: The Subject for statements in RELS-EXT must be a Fedora digital object.

      SubjectPredicateObjectCardinality
      info:fedora/$PID(any non-reserved predicate)(any uri or literal)Zero or More

    4. Content Model Architecture Triples



      Note: These system-recognized predicates are specified in RELS-EXT. If an object does not specify a fedora-model:hasContentModel value in RELS-EXT, an appropriate default value will be assigned in the Resource Index.

      SubjectPredicateObjectCardinality
      info:fedora/$PIDfedora-model:hasContentModelinfo:fedora/$CMODEL_PIDExactly One
      info:fedora/$PIDfedora-model:hasBDefinfo:fedora/$BDEF_PIDZero or More
      info:fedora/$PIDfedora-model:isContractorinfo:fedora/$CMODEL_PIDZero or More

    5. Datastream Triples



      SubjectPredicateObjectCardinality
      info:fedora/$PIDfedora-view:disseminatesinfo:fedora/$PID/$DSIDExactly One
      info:fedora/$PID/$DSIDfedora-view:disseminationTypeinfo:fedora/*/$DSIDExactly One
      info:fedora/$PID/$DSIDfedora-view:mimeType(any mime type string)Exactly One
      info:fedora/$PID/$DSIDfedora-view:lastModifiedDate(date modified in UTC)Exactly One
      info:fedora/$PID/$DSIDfedora-model:statefedora-model:Active or fedora-model:Inactive or fedora-model:DeletedExactly One
      info:fedora/$PID/$DSIDfedora-view:isVolatile(true if R or E, false if M or X)Exactly One

  4. Calculating Triples/Object

    You can use the following table to estimate the number of triples for each kind of object in your Fedora repository.

    Object# of Triples
    Every object automatically gets the following triples:
    • Base: 6
    • Dublin Core (dc:title and dc:identifier): 2
    • Content Model Architecture (fedora-model:hasContentModel): 1
    • Datastream Triples (for DC): 6
    		 15
    If the DC datastream has any elements besides the standard dc:title and dc:identifier, add 1 for each additional element. 
    If the object has a RELS-EXT datastream, add 7, then add 1 for each statement asserted therein (except fedora-model:hasContentModel, which has already been counted above). 
    For each additional datastream, add 7.