METHOD AND APPARATUS FOR SUPPORTING DISTRIBUTED DEDUCTIVE CLOSURES USING MULTIDIMENSIONAL RESULT CURSORS

• US 20110314002A1
• Filed: 06/18/2010
• Published: 12/22/2011
• Est. Priority Date: 06/18/2010
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Oliver, Ian Justin, Lassila, Ora, Mannermaa, Mika Juhani, Boldyrev, Sergey
• Granted Patent: US 9,959,325 B2
• Time in Patent Office: Days
• US Class Current: 707/722
• CPC Class Codes: G06F 16/2471 Distributed queries
• CPC Class Codes: G06F 16/283 Multi-dimensional databases or data warehouses, e.g. MOLAP or ROLAP

Abstract

A method comprises selecting at least a first data set and a second data set on which to apply a query. The method also comprises causing generating of a first cursor based and a second cursor based on a first application of the query on the first data set and a second cursor based on a second application of the query on the second data set. A third cursor based on a combination of a result set returned by the first cursor and second cursor is then generated in response to the query.

Claims

1. A method comprising:

selecting at least a first data set and a second data set on which to apply a query;

causing, at least in part, generating of a first cursor based, at least in part, on a first application of the query on the first data set and a second cursor based, at least in part, on a second application of the query on the second data set, wherein the first cursor and the second cursor point to respective query result sets within the first data set and the second data; and

generating a third cursor based, at least in part, on the first cursor and the second cursor, wherein the third cursor represents a combined result set for the query.

2. A method of claim 1, further comprising:

causing, at least in part, modification of the query based, at least in part, on one or more characteristics of the first data set, the second data set, or a combination thereof,

wherein the first application of the query, the second application of the query, or a combination thereof is further based on the modification.

3. A method of claim 1, further comprising:

determining status information with respect to the first application, the second application, or a combination thereof; and

associating the status information with the first cursor, the second cursor, the third cursor, or a combination thereof.

4. A method of claim 1, wherein the status information includes a query completion status, an amount of data responsive to the query, an extent of available data, a completion time, an error resulting from lack of data access or availability, or a combination thereof.

5. A method of claim 1, further comprising:

applying one or more deductive closures over the respective query result sets,

wherein the generating of the first cursor, the second cursor, the third cursor, or a combination thereof is further based on the one or more deductive closures.

6. A method of claim 1, wherein the first data set or the second data set comprise data types including local data, cached local data, remote data, cached remote data, or a combination thereof, the method further comprising:

determining the data types of the respective query result sets,

wherein the generating of the first cursor, the second cursor, the third cursor, or a combination thereof is further based on the determination.

7. A method of claim 1, further comprising:

receiving the respective query result sets as one or more streams;

causing, at least in part, traversal of the first cursor, the second cursor, the third cursor, or a combination thereof as the one or more streams are received; and

updating the traversal based, at least in part, on receipt of additional portions of the one or more streams.

8. A method of claim 1, further comprising:

detecting overlap among the respective query result sets,

wherein the generating of the third cursor further comprises compacting the respective result sets associated with the third cursor based, at least in part, on the overlap.

9. A method of claim 1, further comprising:

selecting a third data set on which to apply the query; and

causing, at least in part, generating of a fourth cursor based, at least in part, on a third application of the query on the third data set, the fourth cursor pointing to the respective query results sets within the third data set,

wherein the generating of the third cursor is further based on the fourth cursor.

10. An apparatus comprising:

at least one processor; and

at least one memory including computer program code,

wherein the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following,

select at least a first data set and a second data set on which to apply a query;

cause, at least in part, generating of a first cursor based, at least in part, on a first application of the query on the first data set and a second cursor based, at least in part, on a second application of the query on the second data set, wherein the first cursor and the second cursor point to respective query result sets within the first data set and the second data; and

generate a third cursor based, at least in part, on the first cursor and the second cursor, wherein the third cursor represents a combined result set for the query.

11. An apparatus of claim 10, wherein the apparatus is further caused to:

cause, at least in part, modification of the query based, at least in part, on one or more characteristics of the first data set, the second data set, or a combination thereof,

wherein the first application of the query, the second application of the query, or a combination thereof is further based on the modification.

12. An apparatus of claim 10, wherein the apparatus is further caused to:

determine status information with respect to the first application, the second application, or a combination thereof; and

associate the status information with the first cursor, the second cursor, the third cursor, or a combination thereof.

13. An apparatus of claim 10, wherein the status information includes a query completion status, an amount of data responsive to the query, an extent of available data, a completion time, an error resulting from lack of data access or availability, or a combination thereof.

14. An apparatus of claim 10, wherein the apparatus is further caused to:

apply one or more deductive closures over the respective query result sets,

wherein the generating of the first cursor, the second cursor, the third cursor, or a combination thereof is further based on the one or more deductive closures.

15. An apparatus of claim 10, wherein the first data set or the second data set comprise data types including local data, cached local data, remote data, cached remote data, or a combination thereof, and wherein the apparatus is further caused to:

determine the data types of the respective query result sets,

wherein the generating of the first cursor, the second cursor, the third cursor, or a combination thereof is further based on the determination.

16. An apparatus of claim 10, wherein the apparatus is further caused to:

receive the respective query result sets as one or more streams;

cause, at least in part, traversal of the first cursor, the second cursor, the third cursor, or a combination thereof as the one or more streams are received; and

update the traversal based, at least in part, on receipt of additional portions of the one or more streams.

17. An apparatus of claim 10, wherein the apparatus is further caused to:

detect overlap among the respective query result sets,

wherein the generating of the third cursor further comprises compacting the respective result sets associated with the third cursor based, at least in part, on the overlap.

18. An apparatus of claim 10, wherein the apparatus is further caused to:

select a third data set on which to apply the query; and

cause, at least in part, generating of a fourth cursor based, at least in part, on a third application of the query on the third data set, the fourth cursor pointing to the respective query results sets within the third data set,

wherein the generating of the third cursor is further based on the fourth cursor.

19. A computer-readable storage medium carrying one or more sequences of one or more instructions which, when executed by one or more processors, cause an apparatus to perform at least the following:

selecting at least a first data set and a second data set on which to apply a query;

causing, at least in part, generating of a first cursor based, at least in part, on a first application of the query on the first data set and a second cursor based, at least in part, on a second application of the query on the second data set, wherein the first cursor and the second cursor point to respective query result sets within the first data set and the second data; and

generating a third cursor based, at least in part, on the first cursor and the second cursor, wherein the third cursor represents a combined result set for the query.

20. A computer-readable storage medium of claim 19, wherein the apparatus is caused to further perform:

causing, at least in part, modification of the query based, at least in part, on one or more characteristics of the first data set, the second data set, or a combination thereof,

wherein the first application of the query, the second application of the query, or a combination thereof is further based on the modification.

21-42. -42. (canceled)