Extensible RDF Databases

A non-transitory computer-readable storage medium that stores instructions which, when executed by one or more processors, cause:

• a database management system receiving, from a user, definition information for a definition of a new database data type;
• wherein the definition information includes a first mapping between one or more attributes of the new database data type and one or more attributes of a particular base data structure of the database management system;
• wherein the definition information includes a second mapping between one or more attributes of the particular base data structure of the database management system and the one or more attributes of the new database data type;
• storing, in an instance of the particular base data structure of the database management system, a particular subject-predicate-object expression that comprises a particular data associated with the new database data type;
• wherein each subject-predicate-object expression corresponds to a subject, a predicate, and an object;
• wherein a predicate describes a first relationship between a corresponding subject and object;
• wherein the step of storing further comprises:
• identifying the particular subject-predicate-object expression as including the particular data associated with the new database data type;
• in response to identifying the particular subject-predicate-object expression, extracting, based on the first mapping, a value of a particular attribute from the particular data of the particular subject-predicate-object expression;
• and
• based on the first mapping, storing the value of the particular attribute in the instance of the particular base data structure;
• receiving a request for at least a portion of the particular data of the particular subject-predicate-object expression;
• in response to receiving the request, identifying the instance of the particular base data structure;
• based on the second mapping, reconstructing the at least a portion of the particular data of the particular subject-predicate-object expression from the instance of the particular base data structure;
• and
• returning the reconstructed at least a portion of the particular data in response to the request.