Hybrid Push/Pull Execution of Continuous SQL Queries

• US 20100138405A1
• Filed: 12/03/2008
• Published: 06/03/2010
• Est. Priority Date: 12/03/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Mihaila, George Andrei, Stanoi, Ioana Roxana
• Granted Patent: US 8,392,402 B2
• Time in Patent Office: Days
• US Class Current: 707/713
• CPC Class Codes: G06F 16/24568 Data stream processing; Continuous queries

Abstract

Illustrative embodiments provide a computer-implemented method for hybrid push/pull of continuous structured query language queries. The computer-implemented method receives stream input, wherein the stream input comprises events of interest, builds and a state machine and stream plans, based on an original query, and replicates the stream input. Responsive to a push sub-query trigger, the computer-implemented method submits a pull sub-query to the database to produce a result, and sends the result to a requester.

Claims

1. A computer-implemented method for hybrid push/pull of continuous structured query language queries, the computer-implemented method comprising:

receiving stream input, wherein the stream input comprises events of interest;

building stream plans based on an original query and a state machine;

replicating the stream input;

responsive to a push sub-query trigger, submitting a pull sub-query to a database to produce a result; and

sending the result to a requester.

2. The computer-implemented method of claim 1, wherein building stream plans further comprises:

creating a push sub-query representing a portion of the original query;

creating a set of pull sub-queries, representing a portion of the original query; and

combining the push sub-query and the set of pull sub-queries to create a hybrid push/pull query, wherein the hybrid push/pull query is semantically equivalent to the original query.

3. The computer-implemented method of claim 1, wherein replicating the stream input to the database and the state machine further comprises:

copying the input stream to produce a set of input streams, wherein one of the set of input streams is directed to the database and one of the set of input streams is directed to the state machine.

4. The computer-implemented method of claim 1, wherein responsive to a push sub-query trigger further comprises:

determining whether a pattern of the push sub-query matches an event in the one of the set of input streams directed to the state machine to form a pattern match; and

responsive to the pattern match, creating a push sub-query trigger.

5. The computer-implemented method of claim 1, wherein submitting a pull sub-query to the database to produce a result further comprises:

submitting the set of pull sub-queries.

6. The computer-implemented method of claim 1, wherein building stream plans based on an original query further comprises:

decomposing the original query according to selectivities; and

evaluating costs of stream plans according to the selectivities.

7. The computer-implemented method of claim 1, wherein the original query is a continuous query.

8. A data processing system for hybrid push/pull of continuous structured query language queries, the data processing system comprising:

a bus;

a memory connected to the bus, wherein the memory comprises computer executable instructions;

a communication unit connected to the bus;

a database connected to the bus;

a processor unit connected to the bus, wherein the processor unit executes the computer executable instructions to direct the data processing system to;

receive stream input, wherein the stream input contains events of interest;

build stream plans based on an original query and a state machine;

replicate the stream input;

responsive to a push sub-query trigger, submit a pull sub-query to the database to produce a result; and

send the result to a requester.

9. The data processing system of claim 8, wherein executing the computer executable instructions to direct the data processing system to build stream plans further comprises:

create a push sub-query representing a portion of the original query;

create a set of pull sub-queries, representing a portion of the original query; and

combine the push sub-query and the set of pull sub-queries to create a hybrid push/pull query, wherein the hybrid push/pull query is semantically equivalent to the original query.

10. The data processing system of claim 8, wherein executing the computer executable instructions to direct the data processing system to replicate the stream input to the database and the state machine further comprises:

copy the input stream to produce a set of input streams, wherein one of the set of input streams is directed to the database and one of the set of input streams is directed to the state machine.

11. The data processing system of claim 8, wherein executing the computer executable instructions to direct the data processing system to be responsive to a push sub-query trigger further comprises:

determine whether a pattern of the push sub-query matches an event in the one of the set of input streams directed to the state machine to form a pattern match; and

responsive to the pattern match, create a push sub-query trigger.

12. The data processing system of claim 8, wherein executing the computer executable instructions to direct the data processing system to submit a pull sub-query to the database to produce a result further comprises:

submit the set of pull sub-queries.

13. The data processing system of claim 8, wherein executing the computer executable instructions to direct the data processing system to build stream plans based on an original query further comprises:

decompose the original query according to selectivities; and

evaluate costs of stream plans according to the selectivities.

14. The data processing system of claim 8, wherein the original query is a continuous query.

15. A computer-program product for hybrid push/pull of continuous structured query language queries, the computer program product comprising:

a computer usable medium having computer executable instructions stored thereon, the computer executable instructions comprising;

computer executable instructions for receiving stream input, wherein the stream input comprises events of interest;

computer executable instructions for building stream plans based on an original query and a state machine;

computer executable instructions for replicating the stream input;

computer executable instructions responsive to a push sub-query trigger, for submitting a pull sub-query to a database to produce a result; and

computer executable instructions for sending the result to a requester.

16. The computer program product of claim 15, wherein computer executable instructions for building stream plans further comprises:

computer executable instructions for creating a push sub-query representing a portion of the original query;

computer executable instructions for creating a set of pull sub-queries, representing a portion of the original query; and

computer executable instructions for combining the push sub-query and the set of pull sub-queries to create a hybrid push/pull query, wherein the hybrid push/pull query is semantically equivalent to the original query.

17. The computer program product of claim 15, wherein computer executable instructions for replicating the stream input to the database and the state machine further comprises:

computer executable instructions for copying the input stream to produce a set of input streams, wherein one of the set of input streams is directed to a database and one of the set of input streams is directed to the state machine.

18. The computer program product of claim 15, wherein responsive to a push sub-query trigger further comprises:

computer executable instructions for determining whether a pattern of the push sub-query matches an event in the one of the set of input streams directed to the state machine to form a pattern match; and

computer executable instructions responsive to the pattern match, for creating a push sub-query trigger.

19. The computer program product of claim 15, wherein computer executable instructions for submitting a pull sub-query to the database to produce a result further comprises:

computer executable instructions for submitting the set of pull sub-queries.

20. The computer program product of claim 15, wherein computer executable instructions for building stream plans based on an original query further comprises:

computer executable instructions for decomposing the original query according to selectivities, wherein the original query is a continuous query; and

computer executable instructions for evaluating costs of stream plans according to the selectivities.