QUERY PROCESSING WITH SPECIALIZED QUERY OPERATORS

• US 20090319499A1
• Filed: 06/24/2008
• Published: 12/24/2009
• Est. Priority Date: 06/24/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Torgersen, Mads, Dyer, John W., Hejlsberg, Anders, Warren, Matthew J., Meijer, Erik
• Granted Patent: US 8,713,048 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/24526 Internal representations for queries

Abstract

Queries targeting various data sources are processed in a query processing pipeline that parses the query into a set of operations (e.g., an expression tree or a translated SQL query) using a set of query operators, each handling a particular type of operation. The query operators are often designed in an unspecialized manner, such that each query operator handles one query operation in an atomic, generic manner (e.g., sorting generic data items for an ORDER BY clause.) More efficient queries may be devised by including specialized queries that operate in common but special cases, such as a sorting of a particular data type (e.g., a floating-point number sort) or a sequence of two or more operations that are often performed together (e.g., a WHERE test of an attribute followed by a SELECT of the same attribute.) The use of specialized operators may result in the formulation of more efficient queries.

Claims

1. A system for generating a query processing solution for a query, comprising:

a query operator set comprising;

at least one unspecialized query operator configured to perform a query task on at least one unspecialized data type, and

at least one specialized query operator configured to perform at least one query task when at least one specialization criterion is satisfied; and

a query operator selecting component configured to;

select a specialized query operator for respective query terms satisfying the at least one specialization criterion of the specialized query operator; and

select an unspecialized query operator for respective query terms for which a specialized query operator has not been selected; and

generate the query processing solution as a sequence of selected query operators.

2. The system of claim 1, the query comprising a language-integrated query.

3. The system of claim 1, the query comprising an in-memory query against at least one queryable local object.

4. The system of claim 1, the query processing solution comprising an expression tree specifying the sequence operators corresponding to the query terms of the query.

5. The system of claim 1, at least one specialization criterion of a specialized query operator specifying at least two query tasks specified in at least two query terms.

6. The system of claim 1, at least one specialization criterion of a specialized query operator specifying at least one data type involved in the query task.

7. The system of claim 6, the query operator set comprising:

a first specialized query operator specifying a query task involving a first data type, and

a second specialized query operator specifying the query task involving a second data type that is more specific than the first data type of the first specialized query operator.

8. The system of claim 6, the at least one specialized query operator specifying a query task comprising a data set typecasting with respect to a data type.

9. The system of claim 8, the query task applying to the data set comprising objects of the data type.

10. The system of claim 6, the query task based on at least one data type property of the data set.

11. The system of claim 1, the query operator selecting component configured to:

identify specialized query operators handling at least two query tasks specified in at least two query terms of the query; and

upon identifying a specialized query operator, select the specialized query operator for the at least two query terms of the query.

12. The system of claim 1:

at least one query operator configured, upon selection for at least one query task, to;

identify a specialized query operator capable of processing the at least one query task and at least one additional query task of the query; and

upon identifying a specialized order query operator, select the specialized query operator for the at least one query task and the at least one additional query task; and

the query operator selecting component configured to;

select at least one unspecialized query operator for respective query terms of the query; and

upon receiving from a query operator a specialized query operator for the least one query term and the at least one additional query term, select the specialized query operator for the at least one query term and the at least one additional query term.

13. The system of claim 1, comprising:

a data store targeted by the query, and

a query applying component configured to apply the query processing solution to the data store.

14. The system of claim 1, at least one query operator generated by at least one data type of a data set involved in the query.

15. The system of claim 14, at least one unspecialized query operator of the query operator set configured to:

detect at least one data type involved in the query, and

select a specialized query operator configured to perform at least one query task involving the data type.

16. A method of generating a query processing solution for a query from a query operator set comprising at least one unspecialized query operator configured to perform a query task on at least one unspecialized data type and at least one specialized query operator configured to perform at least one query task when at least one specialization criterion is satisfied, the method comprising:

selecting a specialized query operator for respective query terms satisfying the at least one specialization criterion of the specialized query operator;

selecting an unspecialized query operator for respective query terms for which a specialized query operator has not been selected; and

generating the query processing solution as a sequence of selected query term operators.

17. The method of claim 16, at least one specialization criterion of a specialized query operator specifying at least one data type involved in the query task.

18. The method of claim 16, at least one specialization criterion of a specialized query operator specifying at least two query tasks specified in at least two query terms.

19. The method of claim 16, the selecting comprising:

identifying specialized query operators handling at least two query tasks specified in at least two query terms of the query; and

upon identifying a specialized query operator, selecting the specialized query operator for the at least two query terms of the query.

20. A system for generating a query processing solution for a language-integrated query, comprising:

a data store targeted by the query;

a query operator set comprising;

at least one unspecialized query operator configured to perform a query task on at least one unspecialized data type, including at least one unspecialized query operator configured to;

detect at least one data type involved in the query, and

select a specialized query operator configured to perform at least one query task involving the data type; and

at least one specialized query operator configured to perform at least one query task when at least one specialization criterion is satisfied, including at least one specialized query operator configured, upon selection for at least one query task, to;

identify a specialized query operator capable of processing the at least one query task and at least one additional query task of the query; and

upon identifying a specialized order query operator, select the specialized query operator for the at least one query task and the at least one additional query task;

a query operator selecting component configured to;

select at least one unspecialized query operator for respective query terms of the query; and

upon receiving from a query operator a specialized query operator for the least one query term and the at least one additional query term, select the specialized query operator for the at least one query term and the at least one additional query term;

a query operator selecting component configured to;

identify specialized query operators handling at least two query tasks specified in at least two query terms of the query;

upon identifying a specialized query operator, select the specialized query operator for the at least two query terms of the query;

upon failing to identify a specialized query selector, select an unspecialized query operator for respective query terms for which a specialized query operator has not been selected; and

generate the query processing solution as an expression tree comprising a sequence of selected query operators; and

a query applying component configured to apply the processing solution to the data store.