MANAGING CONTINUOUS QUERIES IN THE PRESENCE OF SUBQUERIES

• US 20140095473A1
• Filed: 03/14/2013
• 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 9,990,402 B2
• Time in Patent Office: Days
• US Class Current: 707/718
• CPC Class Codes: B29D 2030/0682 Inner liners tubeless tyres with impervious liner or coating on the tyre B60C5/14
• CPC Class Codes: B29D 30/0681 Parts of pneumatic tyres; accessories, auxiliary operations
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B60C 1/0008 Compositions of the inner liner
• CPC Class Codes: B60C 5/14 with impervious liner or coating on the inner wall of the tyre
• CPC Class Codes: G06F 16/242 Query formulation
• CPC Class Codes: G06F 16/245 Query processing
• CPC Class Codes: G06F 16/2453 Query optimisation
• CPC Class Codes: G06F 16/24535 of sub-queries or views
• CPC Class Codes: G06F 16/24539 using cached or materialised query results
• CPC Class Codes: G06F 16/2455 Query execution
• CPC Class Codes: G06F 16/24553 of query operations
• CPC Class Codes: G06F 16/2456 Join operations
• CPC Class Codes: G06F 16/24568 Data stream processing; Continuous queries
• CPC Class Codes: G06F 16/2474 Sequence data queries, e.g. querying versioned data
• CPC Class Codes: G06F 16/2477 Temporal data queries
• CPC Class Codes: G06F 16/248 Presentation of query results
• CPC Class Codes: G06F 16/25 Integrating or interfacing systems involving database management systems
• CPC Class Codes: G06F 16/313 Selection or weighting of terms for indexing
• CPC Class Codes: G06F 16/9024 : Graphs; Linked lists G06F16/9027 takes precedence
• CPC Class Codes: G06F 16/951 : Indexing; Web crawling techniques

Abstract

Techniques for managing continuous queries that include subqueries are provided. In some examples, a continuous query that includes at least a subquery may be identified. Additionally, the subquery may be processed to obtain a first result or generate a logical subquery plan. Further, in some instances, the continuous query may then be processed based at least in part on the first result from the subquery or by merging a logical continuous query plan with the logical subquery plan. This may result in obtaining a second result via querying a data source with the continuous query that is based at least in part on the first result from the subquery and/or the merged plans.

Claims

1. A system, comprising:

a memory storing a plurality of instructions; and

one or more processors configured to access the memory, wherein the one or more processors are further configured to execute the plurality of instructions to at least;

identify a continuous query including at least a subquery;

process the subquery to obtain a logical plan; and

process the continuous query based at least in part on merging a continuous query plan with the logical plan to obtain a result.

2. The system of claim 1, wherein at least one of the continuous query or the subquery is configured to process business event data of a stream, business event data of a relation associated with the stream, or business event data of a database.

3. The system of claim 2, wherein the relation comprises an unordered, time-varying set of tuples associated with a stream of business event data.

4. The system of claim 1, wherein identifying the continuous query includes at least receiving the continuous query or generating the continuous query.

5. The system of claim 1, wherein the one or more processors are further configured to execute the plurality of instructions to at least provide the result to a user interface of a user that provided the continuous query.

6. The system of claim 5, wherein the user interface is configured to display real-time data based at least in part on the result.

7. The system of claim 1, wherein the continuous query is dependent on a first result from the subquery.

8. The system of claim 1, wherein the subquery is configured as a continuous subquery and is included within a “

from”

clause or a “

set”

clause of the continuous query.

9. The system of claim 1, wherein the subquery is configured to obtain a set of first results over time, and wherein less than all of the set of first results are stored in memory and accessible for processing the continuous query to obtain the result.

10. The system of claim 9, wherein the one or more processors are further configured to execute the plurality of instructions to at least reprocess the subquery to obtain a second logical plan over time based at least in part on an indication that data associated with the subquery has changed.

11. A computer-readable memory storing a plurality of instructions executable by one or more processors, the plurality of instructions comprising:

instructions that cause the one or more processors to receive a continuous query statement with at least one nested subquery statement from a user associated with business event data;

instructions that cause the one or more processors to process the at least one nested subquery statement to obtain at least a logical subquery plan corresponding to the business event data; and

instructions that cause the one or more processors to process the continuous query based at least in part on merging a continuous query plan with the logical subquery plan to obtain at least a second result corresponding to the business event data.

12. The computer-readable memory of claim 11, wherein the at least one nested subquery includes at least another subquery.

13. The computer-readable memory of claim 11, wherein at least data associated with the logical subquery plan are included in a dimension table upon which the continuous query depends.

14. The computer-implemented method of claim 13, wherein the plurality of instructions further comprise instructions that cause the one or more processors to receive an exception when data of the dimension table changes.

15. The computer-implemented method of claim 14, wherein the dimension table is refreshed by re-processing the at least one nested subquery statement based at least in part on the exception.

16. A computer-implemented method, comprising:

receiving a continuous query statement from a user associated with business event data;

determining whether the continuous query includes one or more continuous subqueries; and

when the continuous query includes one or more continuous subqueries;

processing the continuous subquery to obtain a set of first results based at least in part on implementing a clause of the continuous subquery on a stream associated with the business event data of the user; and

processing the continuous query by utilizing at least a subset of the set of first results to obtain second results based at least in part on implementing a clause of the continuous query on the stream associated with the business event data of the user.

19. The computer-implemented method of claim 16, further comprising loading only a subset of the first results in memory when the subset is associated with a low probability of changing.

20. The computer-implemented method of claim 16, wherein the stream associated with the business event data of the user includes one or more archived relations.

17. The computer-implemented method of 16, further comprising not instantiating an operator of the continuous query when it relies on a dimension table until a time after receiving an indication that data in the dimension table has changed.

18. The computer-implemented method of 16, further comprising loading less than all of the set of first results in memory.