Information retrieval from relational databases using semantic queries

• US 20080040308A1
• Filed: 08/03/2006
• Published: 02/14/2008
• Est. Priority Date: 08/03/2006
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Liu, Zhen, Ranganathan, Anand
• Granted Patent: US 8,510,321 B2
• Time in Patent Office: Days
• US Class Current: 707/1
• CPC Class Codes: G06F 16/284 Relational databases

Abstract

In the realm of managing relational databases, a system that uses both the data in a relational database and domain knowledge in ontologies to return semantically relevant results to a user'"'"'s query. Broadly contemplated herein, in essence, is a system that bridges a semantic gap between queries users want to express and queries that can be answered by the database using domain knowledge contained in ontologies. In accordance with a preferred embodiment of the present invention, such a system extends relational databases with the ability to answer semantic queries that are represented in SPARQL, an emerging Semantic Web query language. Particularly, users may express their queries in SPARQL, based on a semantic model of the data, and they get back semantically relevant results. Also broadly contemplated herein is the definition of different categories of results that are semantically relevant to a user'"'"'s query and an effective retrieval of such results.

Claims

1. An apparatus for accessing and managing a relational database, said apparatus comprising:

an arrangement for querying a relational database; and

an arrangement for accessing query results from a relational database;

said accessing arrangement acting to;

access at least one ontology;

extract domain knowledge from at least one ontology; and

employ domain knowledge so extracted in obtaining query results from the relational database.

2. The apparatus according to claim 1, wherein:

said querying arrangement acts to query a relational database in accordance with a predetermined querying medium; and

said accessing arrangement acts to interface with a relational database in a manner to obtain querying results relevant to the predetermined querying medium.

3. The apparatus according to claim 2, wherein the predetermined querying medium is SPARQL.

4. The apparatus according to claim 1, wherein said accessing arrangement further acts to define and obtain query results in terms of at least one category relevant to a query.

5. The apparatus according to claim 4, wherein the at least one category relates to at least one ontology accessed by said accessing arrangement.

6. The apparatus according to claim 5, wherein said accessing arrangement acts to obtain supplementary query results that are related to actual query results.

7. The apparatus according to claim 6, wherein said accessing arrangement acts to apply a query generalization strategy which modifies an original query.

8. The apparatus according to claim 7, wherein the query generalization strategy comprises subsumption hierarchy based constraint generalization.

9. The apparatus according to claim 7, wherein the query generalization strategy comprises property hierarchy based constraint generalization.

10. The apparatus according to claim 7, wherein the query generalization strategy comprises individual-type based constraint generalization.

11. The apparatus according to claim 1, wherein said accessing arrangement comprises a description logic reasoner.

12. The apparatus according to claim 11, wherein said accessing arrangement comprises a description horn logic reasoner.

13. The apparatus according to claim 12, wherein said accessing arrangement comprises a Minerva reasoner.

14. The apparatus according to claim 11, further comprising a standby description logic reasoner for backing up said description logic reasoner.

15. The apparatus according to claim 1, further comprising a wrapper arrangement which acts to translate data from a relational database into a predetermined format for said accessing arrangement.

16. The apparatus according to claim 15, wherein said wrapper arrangement acts to translate data from a relational database into triples.

17. A method of accessing and managing a relational database, said method comprising the steps of:

querying a relational database; and

accessing query results from the relational database;

said accessing step comprising;

accessing at least one ontology;

extracting domain knowledge from at least one ontology; and

employing domain knowledge so extracted in obtaining query results from the relational database.

18. The method according to claim 17, wherein:

said querying step comprises querying the relational database in accordance with a predetermined querying medium; and

said step of accessing query results comprises interfacing with the relational database in a manner to obtain querying results relevant to the predetermined querying medium.

19. The method according to claim 18, wherein the predetermined querying medium is SPARQL.

20. The method according to claim 17, wherein said step of accessing query results further comprises defining and obtaining query results in terms of at least one category relevant to a query.

21. The method according to claim 20, wherein the at least one category relates to at least one ontology accessed in said accessing step.

22. The method according to claim 21, wherein said step of accessing query results comprises obtaining supplementary query results that are related to actual query results.

23. The method according to claim 22, wherein said step of obtaining supplementary query results comprises applying a query generalization strategy which modifies an original query.

24. The method according to claim 23, wherein the query generalization strategy comprises subsumption hierarchy based constraint generalization.

25. The method according to claim 23, wherein the query generalization strategy comprises property hierarchy based constraint generalization.

26. The method according to claim 23, wherein the query generalization strategy comprises individual-type based constraint generalization.

27. The method according to claim 17, wherein said step of accessing query results comprises employing a description logic reasoner.

28. The method according to claim 27, wherein said step of employing a description logic reasoner comprises employing a description horn logic reasoner.

29. The method according to claim 28, wherein said step of employing a description horn logic reasoner comprises employing a Minerva reasoner.

30. The method according to claim 27, step of accessing query results further comprises employing a standby description logic reasoner for backing up said description logic reasoner.

31. The method according to claim 17, further comprising the step of translating data from a relational database into a predetermined format.

32. The method according to claim 31, wherein said translating step comprises translating data from a relational database into triples.

33. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for accessing and managing a relational database, said method comprising the steps of:

querying a relational database; and

accessing query results from the relational database;

said accessing step comprising;

accessing at least one ontology;

extracting domain knowledge from at least one ontology;

employing domain knowledge so extracted in obtaining query results from the relational database.