STATE INITIALIZATION FOR CONTINUOUS QUERIES OVER ARCHIVED VIEWS

• US 20140095444A1
• Filed: 09/25/2013
• Published: 04/03/2014
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Srinivasan, Anand, Shukla, Vikram, Deshmukh, Unmesh Anil
• Granted Patent: US 9,805,095 B2
• Time in Patent Office: Days
• US Class Current: 707/661
• CPC Class Codes: G06F 16/2308 Concurrency control transaction processing G06F9/466
• CPC Class Codes: G06F 16/24542 Plan optimisation
• CPC Class Codes: G06F 16/24544 Join order optimisation
• CPC Class Codes: G06F 16/24568 Data stream processing; Continuous queries
• CPC Class Codes: G06F 16/951 Indexing; Web crawling techniques

Abstract

A method may include receiving a continuous query identified by an archived view. The method may also include creating the archived view, the archived view identified by a join query related to two or more archived relations associated with an application and/or generating a query plan for the continuous query. The method may also include identifying a view root operator in the archived view, the view root operator identified as a join operator in the archived view and/or identifying a query operator in the query plan that topologically precedes the view root operator. Further, the method may include constructing an archiver query for the identified query operator that topologically precedes the view root operator, executing the archiver query to obtain a result set of data records related to the application, and/or generating a snapshot output of one or more data values related to the application.

Claims

1. A computer-implemented method, comprising:

receiving, by a computer system configured to execute computer-executable instructions, a continuous query, the continuous query being identified based at least in part on an archived view;

creating the archived view, the archived view being identified based at least in part on a join query related to two or more archived relations associated with an application;

generating a query plan for the continuous query;

identifying a view root operator in the archived view, the view root operator being identified as a join operator in the archived view;

identifying a query operator in the query plan that topologically precedes the view root operator;

constructing an archiver query for the identified query operator that topologically precedes the view root operator;

executing the archiver query to obtain a result set of data records related to the application; and

generating a snapshot output of one or more data values related to the application based at least in part on the result set of data records related to the application.

2. The computer-implemented method of claim 1, further comprising:

traversing the query plan in topological order to identify the view root operator, the view root operator being identified by an output operator to store event information related to the application;

inserting a buffer operator between the view root operator and the output operator in the query plan; and

storing the event information from the view root operator in the buffer operator.

3. The computer-implemented method of claim 1, further comprising:

identifying a second query operator in a second continuous query concurrently executing as being the same type as the query operator identified in the query plan, the second continuous query being identified based at least in part on the archived view; and

generating a combined query plan based at least in part on the query operator identified in the query plan being the same type as the second query operator in the second continuous query.

4. The computer-implemented method of claim 1, further comprising initializing a state of the query operator based at least in part on the result set of data records.

5. The computer-implemented method of claim 4, further comprising generating the snapshot output of one or more data values related to the application based at least in part on the state of the identified query operator.

6. The computer-implemented method of claim 4, further comprising initializing the state by constructing a list of tuples for the identified query operator from the result set of data records, wherein at least one tuple in the list of tuples is constructed based at least in part on a subset of attributes in the result set of data records.

7. The computer-implemented method of claim 1, further comprising displaying the snapshot output of the one or more data values related to the application to a user of the application via a display device.

8. The computer-implemented method of claim 1, further comprising processing incoming real-time events related to the application based at least in part on the snapshot output of the one or more data values.

12. The computer-readable storage medium of claim 1, further comprising instructions that cause the one or more computer systems to generate the snapshot output of one or more data values related to the application based at least in part on the state of the identified query operator.

9. A computer-readable storage medium storing computer-executable instructions that, when executed by one or more computer systems, configure the one or more computer systems to perform at least:

instructions that cause the one or more computer systems to receive a continuous query, the continuous query being identified based at least in part on an archived view;

instructions that cause the one or more computer systems to create the archived view, the archived view being identified based at least in part on a join query related to two or more archived relations associated with an application;

instructions that cause the one or more computer systems to identify a view root operator in the archived view, the view root operator being identified as a join operator in the archived view;

instructions that cause the one or more computer systems to identify a query operator in a query plan for the continuous query that topologically precedes the view root operator;

instructions that cause the one or more computer systems to construct an archiver query for the identified query operator that topologically precedes the view root operator; and

instructions that cause the one or more computer systems to execute the archiver query to obtain a result set of data records related to the application.

10. The computer-readable storage medium of claim 9, further comprising instructions that cause the one or more computer systems to generate a snapshot output of one or more data values related to the application based at least in part on the result set of data records related to the application.

11. The computer-readable storage medium of claim 10, further comprising instructions that cause the one or more computer systems to initialize a state of the query operator based at least in part on the result set of data records.

13. The computer-readable storage medium of claim 11, further comprising instructions that cause the one or more computer systems to initialize the state by constructing a list of tuples for the identified query operator from the result set of data records.

14. The computer-readable storage medium of claim 13, wherein at least one tuple in the list of tuples is constructed based at least in part on a subset of attributes in the result set of data records.

15. The computer-readable storage medium of claim 9, further comprising instructions that cause the one or more computer systems to at least display a snapshot output of one or more data values related to the application based at least in part on the result set of data records related to the application.

16. A system, comprising:

a memory storing a plurality of instructions; and

a processor configured to access the memory, wherein the processor is further configured to execute the plurality of instructions to at least;

receive a continuous query, the continuous query being identified based at least in part on an archived view;

create the archived view, the archived view being identified based at least in part on a join query related to two or more archived relations associated with an application;

receive a continuous query, the continuous query being identified based at least in part on the archived view;

generate a query plan for the continuous query;

identify a view root operator in the archived view, the view root operator being identified as a join operator in the archived view;

identify a query operator in the query plan that topologically precedes the view root operator,

construct an archiver query for the identified query operator that topologically precedes the view root operator;

execute the archiver query to obtain a result set of data records related to the application; and

generate a snapshot output of one or more data values related to the application based at least in part on the result set of data records related to the application.

17. The system of claim 16, wherein the processor is further configured to execute the plurality of instructions to at least:

traverse the query plan in topological order to identify the view root operator, the view root operator being identified by an output operator configured to store event information related to the application;

insert a buffer operator between the view root operator and the output operator in the query plan; and

store the event information from the view root operator in the buffer operator.

18. The system of claim 16, wherein the processor is further configured to execute the plurality of instructions to at least:

identify a second query operator in a continuous query concurrently executing as being the same type as the query operator identified in the query plan; and

generate a combined query plan based at least in part on the query operator identified in the query plan being the same type as the second query operator in the continuous query.

19. The system of claim 16, wherein the processor is further configured to execute the plurality of instructions to at least initialize a state of the query operator based at least in part on the result set of data records.

20. The system of claim 19, wherein the processor is further configured to execute the plurality of instructions to at least generate the snapshot output of one or more data values related to the application based at least in part on the state of the identified query operator.