Database-based semantic query answering

摘要

A computer-implemented method, computer-implemented system, and a computer program product for answering a database-based query of a computerized database system. The method includes: generating a canonical individual ind' with respect to a role and a concept, for an existential restriction in an ontology used in the computerized database system; converting implicit data in original data into explicit data using the canonical individual ind' and the ontology; and retrieving an answer meeting all query conditions in a query from the original data and the converted explicit data. The computer-implemented system includes: a canonical individual generation unit; a data conversion engine; and a query unit.

主权项

1. A computer-implemented method for answering a database-based query of a computerized database system, the method comprising:
generating a canonical individual ind' with respect to a role and a concept, for an existential restriction in an ontology used in the computerized database system; converting implicit data in original data into explicit data by using the canonical individual ind' and the ontology; retrieving an answer meeting all query conditions in a query from the original data and the converted explicit data; generating a base path starting from a named individual and ending at a canonical individual according to the original data and the converted explicit data; determining whether the query has a fork; rewriting the query by appending a first query condition if the query has the fork and a root variable of the fork is matched with the canonical individual according to the original data and the converted explicit data, wherein the first query condition is an existing base path is required such that all matching variables in the fork are nodes directly or indirectly located in the base path; configuring a relational graph from data in the form of instance role with respect to the named individual and the canonical individual according to the original data and the converted explicit data, and data in the form of instance type with respect to the canonical individual according to the original data and the converted explicit data; traversing the relational graph and computing a base path starting from the named individual and ending at the canonical individual according to the original data and the converted explicit data; and storing the base path in the form of triples of the base path, a tail of the base path, and nodes directly or indirectly located in the base path.