Method, system and program for executing a query having a union operator

• US 20060101011A1
• Filed: 11/05/2004
• Published: 05/11/2006
• Est. Priority Date: 11/05/2004
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: International Business Machines Corporation
• Inventors: Zuzarte, Calisto Paul, Pirahesh, Mir Hamid, Sharpe, David C., Lindsay, Bruce Gilbert, Liu, Linqi, Sutyanyong, Nattavut, Neugebauer, Robert Paul
• Granted Patent: US 7,539,667 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/24537 of operators
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching

Abstract

Disclosed is a data processing system implemented method, a data processing system and an article of manufacture for executing a query having a union operator. A data processing system implemented method direct the data processing system to execute a query against a database having data objects. The query has sub-queries and having a union operator. The union operator is operable on sub-queries associated with the query. The database is operatively coupled to the data processing system. The data processing system implemented method including grouping the sub-queries of the union operator according to identified structural similarities, the identified structural similarities being based on an analysis of the sub-queries, grouping the data objects of the database according to the grouped sub-queries, replacing the grouped data objects and any sub-queries associated with the grouped data objects with a reference to a representative data object and a representative sub-query, and accessing at least one member of the grouped data objects, the accessing of the at least one member of the grouped data object being based on the reference.

Claims

1. A data processing system implemented method of directing a data processing system to execute a query against a database having data objects, the query having sub-queries and having a union operator, the union operator operable on sub-queries associated with the query, the database being operatively coupled to the data processing system, the data processing system implemented method comprising:

grouping the sub-queries of the union operator according to identified structural similarities, the identified structural similarities being based on an analysis of the sub-queries;

grouping the data objects of the database according to the grouped sub-queries;

replacing the grouped data objects and any sub-queries associated with the grouped data objects with a reference to a representative data object and a representative sub-query; and

accessing at least one member of the grouped data objects, the accessing of the at least one member of the grouped data object being based on the reference.

2. The data processing system implemented method of claim 1 wherein the grouped data objects are further grouped according to statistical similarity, the statistical similarity being based on an analysis of the data objects being referenced by the grouped sub-queries.

3. The data processing system implemented method of claim 1 wherein the union operator is a union all operator.

4. The data processing system implemented method of claim 1 wherein the grouping of the sub-queries comprises:

adding a current sub-query to the grouped sub-queries if the current sub-query is structurally similar with the grouped sub-queries; and

adding the current sub-query to a new group of sub-queries if the current sub-query is structurally dissimilar with the grouped sub-queries.

5. The data processing system implemented method of claim 4 wherein the adding of the current sub-query comprises:

ensuring the current sub-query and members of the grouped sub-queries have common operations which are similar in sequence and property;

ensuring the current sub-query and members of the grouped sub-queries have similar operations which have similar predicates and expressions unless the predicates and the expressions are a part of a partitioning of the union operator; and

ensuring the current sub-query and members of the grouped sub-queries have referenced data objects which are structurally similar.

6. The data processing system implemented method of claim 2 further comprising:

adding a selected data object to the grouped data objects if a statistical method indicates that the selected data object and the members of the grouped data objects are similar; and

adding the selected data object to a new grouping of data objects if the selected data object and the members of the grouped data objects are dissimilar.

7. The data processing system implemented method of claim 1 wherein the replacing the grouped data objects comprises:

identifying a member of the grouped data objects and a sub-query associated with the identified member, the identified member being a representative data object and a representative sub-query;

associating the representative data object with the members of the grouped data objects;

replacing all data objects of the grouped data objects and their associated sub-queries with a reference to the representative data object and the representative sub-query; and

creating, if a partitioning exists in the union operator, the partitioning for the data objects of the group in the representative data object.

8. The data processing system implemented method of claim 1 wherein the accessing of at least one member of the grouped data objects comprises:

determining, if a partitioning exists in the representative data object, which data objects will provide relevant data to the query and retrieving data from the determined data objects; and

retrieving data from each data object selected from the grouped data objects, the each data object being associated with the representative data object.

9. A data processing system for executing a query against a database having data objects, the query having sub-queries and having a union operator, the union operator operable on sub-queries associated with the query, the database being operatively coupled to the data processing system, the data processing system comprising:

a first grouping module for grouping the sub-queries of the union operator according to identified structural similarities, the identified structural similarities being based on an analysis of the sub-queries;

a second grouping module for grouping the data objects of the database according to the grouped sub-queries;

a replacing module for replacing the grouped data objects and any sub-queries associated with the grouped data objects with a reference to a representative data object and a representative sub-query; and

an accessing module for accessing at least one member of the grouped data objects, the accessing of the at least one member of the grouped data object being based on the reference.

10. The data processing system of claim 9 wherein the first grouping module for grouping the data objects further groups the data objects according to statistical similarity, the statistical similarity being based on an analysis of the data objects being referenced by the grouped sub-queries.

11. The data processing system method of claim 9 wherein the union operator is a union all operator.

12. The data processing system of claim 9 wherein the second grouping module for grouping the sub-queries comprises:

an adding module for adding a current sub-query to the grouped sub-queries if the current sub-query is structurally similar with the grouped sub-queries; and

an addition module for adding the current sub-query to a new group of sub-queries if the current sub-query is structurally dissimilar with the grouped sub-queries.

13. The data processing system of claim 12 wherein the adding module for adding the current sub-query comprises:

a first ensuring module for ensuring the current sub-query and members of the grouped sub-queries have common operations which are similar in sequence and property;

a second ensuring module for ensuring the current sub-query and members of the grouped sub-queries have similar operations which have similar predicates and expressions unless the predicates and the expressions are a part of a partitioning of the union operator; and

a third ensuring module for ensuring the current sub-query and members of the grouped sub-queries have referenced data objects which are structurally similar.

14. The data processing system of claim 10 further comprising:

an adding module for adding a selected data object to the grouped data objects if a statistical method indicates that the selected data object and the members of the grouped data objects are similar; and

an addition module for adding the selected data object to a new grouping of data objects if the selected data object and the members of the grouped data objects are dissimilar.

15. The data processing system of claim 9 wherein the replacing module for replacing the grouped data objects comprises:

an identifying module for identifying a member of the grouped data objects and a sub-query associated with the identified member, the identified member being a representative data object and a representative sub-query;

an associating module for associating the representative data object with the members of the grouped data objects;

a replacement module for replacing all data objects of the grouped data objects and their associated sub-queries with a reference to the representative data object and the representative sub-query; and

a creation module for creating, if a partitioning exists in the union operator, the partitioning for the data objects of the group in the representative data object.

16. The data processing system of claim 9 wherein the accessing module for accessing of at least one member of the grouped data objects comprises:

a determining module for determining, if a partitioning exists in the representative data object, which data objects will provide relevant data to the query and retrieving data from the determined data objects; and

a retrieving module for retrieving data from each data object selected from the grouped data objects, the each data object being associated with the representative data object.

17. An article of manufacture for directing a data processing system to execute a query against a database having data objects, the query having sub-queries and having a union operator, the union operator operable on sub-queries associated with the query, the database being operatively coupled to the data processing system, the article of manufacture comprising:

a program usable medium embodying one or more instructions executable by the data processing system, the one or more instructions comprising;

data processing system executable instructions for grouping the sub-queries of the union operator according to identified structural similarities, the identified structural similarities being based on an analysis of the sub-queries;

data processing system executable instructions for grouping the data objects of the database according to the grouped sub-queries;

data processing system executable instructions for replacing the grouped data objects and any sub-queries associated with the grouped data objects with a reference to a representative data object and a representative sub-query; and

data processing system executable instructions for accessing at least one member of the grouped data objects, the accessing of the at least one member of the grouped data object being based on the reference.

18. The article of manufacture of claim 17 wherein the grouped data objects are further grouped according to statistical similarity, the statistical similarity being based on an analysis of the data objects being referenced by the grouped sub-queries.

19. The data processing system implemented method of claim 17 wherein the union operator is a union all operator.

20. The article of manufacture of claim 17 wherein the data processing system executable instructions for grouping of the sub-queries comprises:

data processing system executable instructions for adding a current sub-query to the grouped sub-queries if the current sub-query is structurally similar with the grouped sub-queries; and

data processing system executable instructions for adding the current sub-query to a new group of sub-queries if the current sub-query is structurally dissimilar with the grouped sub-queries.

21. The article of manufacture of claim 20 wherein the data processing system executable instructions for adding of the current sub-query comprises:

data processing system executable instructions for ensuring the current sub-query and members of the grouped sub-queries have common operations which are similar in sequence and property;

data processing system executable instructions for ensuring the current sub-query and members of the grouped sub-queries have similar operations which have similar predicates and expressions unless the predicates and the expressions are a part of a partitioning of the union operator; and

data processing system executable instructions for ensuring the current sub-query and members of the grouped sub-queries have referenced data objects which are structurally similar.

22. The article of manufacture of claim 18 further comprising:

data processing system executable instructions for adding a selected data object to the grouped data objects if a statistical method indicates that the selected data object and the members of the grouped data objects are similar; and

data processing system executable instructions for adding the selected data object to a new grouping of data objects if the selected data object and the members of the grouped data objects are dissimilar.

23. The article of manufacture of claim 17 wherein the data processing system executable instructions for replacing the grouped data objects comprises:

data processing system executable instructions for identifying a member of the grouped data objects and a sub-query associated with the identified member, the identified member being a representative data object and a representative sub-query;

data processing system executable instructions for associating the representative data object with the members of the grouped data objects;

data processing system executable instructions for replacing all data objects of the grouped data objects and their associated sub-queries with a reference to the representative data object and the representative sub-query; and

data processing system executable instructions for creating, if a partitioning exists in the union operator, the partitioning for the data objects of the group in the representative data object.

24. The article of manufacture of claim 17 wherein the data processing system executable instructions for accessing of at least one member of the grouped data objects comprises:

data processing system executable instructions for determining, if a partitioning exists in the representative data object, which data objects will provide relevant data to the query and retrieving data from the determined data objects; and

data processing system executable instructions for retrieving data from each data object selected from the grouped data objects, the each data object being associated with the representative data object.