Contents ix 5.4 From Content Management to Metadata Management ....................................................... 148 5.4.1 Cross Media Challenge and Metadata Ownership ........................................................... 150 5.4.2 Separating Metadata from Content Binaries ......... 151 5.4.3 Preparing for the Future ....................................... 153 5.5 Overall Architecture ............................................ 154 5.6 Our Metadata Ontology ...................................... 157 5.6.1 Instance Metadata and the Schema ..................... 160 5.6.2 Initializing the Framework .................................... 160 5.6.3 Our Default Ontology .......................................... 161 5.6.4 Namespace .......................................................... 161 5.6.5 Metadata Schema Objects ................................... 162 5.6.6 The Most Typical Metadata Schema Objects and Attributes ...................................................... 163 5.6.7 Events .................................................................. 164 5.6.8 Relationships ........................................................ 165 5.6.9 How to Handle Composite Objects ..................... 166 5.6.10 URIs for Fragments ............................................ 167 5.6.11 Extending the Ontology ..................................... 169 5.7 Making a Prototype Implementation .................. 171 5.7.1 Metadata Engine .................................................. 172 5.7.2 Managing Schemas .............................................. 174 5.7.3 Why Use SQL and Especially SQLite as Persistent Storage ................................................. 178 5.7.4 Harvester Manager ............................................... 183 5.7.5 Context Engine .................................................... 185 5.8 Facing Real Life ................................................... 189 5.8.1 Memory Consumption ......................................... 190 5.8.2 Speed .................................................................. 191 5.8.3 Example Usage of Metadata Engine ..................... 192