In addition to enabling the creation and retrieval of topic maps, ITopicMapSystem interface provides methods and properties access to some TMCore system utilities.

The method GetXTMProcessor() retrieves an object implementing the IXTMProcessor interface that allows topic map data to be imported into or exported from the TMCore system using the standard XML Topic Maps (XTM) syntax. Import and export of XTM files is covered in more detail in Chapter 7, Importing and Exporting XTM Files.

The method ExecuteQuery() is used to execute an SQL query against the relational topic map data model exposed by the TMCore system. This method returns an ITMCoreDataReader instance. The relational topic map model, querying and the ITMCoreDataReader interface are dealt with in Chapter 9, Querying.

The property ChangeNotifier returns an instance of the IChangeNotifier interface which can be used to monitor the TMCore system for modifications made to topics and associations by any clients connected to the system. The IChangeNotifier interface is described in more detail in the section called “Change Notification”.