Systems and methods for processing queries

• US 7,966,311 B2
• Filed: 06/17/2003
• Issued: 06/21/2011
• Est. Priority Date: 06/17/2002
• Status: Expired due to Fees

• Current Assignee: Kenneth Haase
• Original Assignee: Kenneth Haase
• Inventors: Haase, Kenneth
• Primary Examiner(s): LOVEL, KIMBERLY M
• Application Number:
  US10/463,555
• Publication Number:
  US 20050044064A1
• Time in Patent Office: 2,926 Days
• Field of Search: 707 1-206, 707/3, 707/713, 707/999.003
• US Class Current: 707/713
• CPC Class Codes: G06F 16/24534 Query rewriting; Transformation
• CPC Class Codes: G06F 16/24552 Database cache management
• CPC Class Codes: G06F 16/2471 Distributed queries

Abstract

The present invention relates to systems and methods for processing queries. One embodiment of the invention provides a system for executing complex procedural queries across a plurality of databases. The system includes: a query processor capable of partial execution of procedural queries; a set of database adaptors capable of optimizing or and referring collections of queries to external databases; and a query cache component in communication with the query processor and the set of database adaptors. The query cache component stores the results of external database queries in a query cache and notes when a query has not been stored and records the same query.

Claims

1. A system for executing complex procedural queries across a plurality of databases, the system comprising one or more processors configured to function as:

a query processor configured to iteratively execute a complex procedural query defined using a general-purpose functional programming language, the complex procedural query comprising a top-level complex procedural query and sub-queries;

a set of database adaptors configured to optimize and refer collections of queries, corresponding to the complex procedural query, to external databases; and

a query cache in communication with the query processor and the set of database adaptors, the query cache configured to store results of the external database queries in the query cache and note unresolved data which the complex procedural query needs but does not have;

wherein the query processor is configured to detect a soft failure,

wherein the query processor is configured to execute a subsequent iteration of the entire complex procedural query, if unresolved data is noted from a previous iteration of the complex procedural query, using the stored results,

wherein the complex procedural query is severable such that at least a first portion of the complex procedural query can proceed even if a second portion of the complex procedural query fails.

2. The system of claim 1 wherein results in the query cache persist between queries.

3. The system of claim 2 wherein the query cache is configured to provide a two-level cache, where a query-specific query cache refers to a global persistent query cache.

4. The system of claim 1 wherein the query processor comprises:

a query buffer for maintaining the top-level complex procedural query;

a query execution unit (QEU) in communication with the query buffer and configured to execute the top-level complex procedural query and the sub-queries; and

a device in communication with the QEU and with the query buffer, the device configured to indicate to the query buffer when at least one of query execution and sub-query execution results in the soft failure;

such that the system continually executes independent sub-queries when a given sub-query results in a soft failure; and

wherein failed sub-queries are referred to the database adaptors when the execution of the top-level query finishes.

5. The system of claim 1 wherein the set of database adaptors configured to optimize and refer the collections of queries to external databases is configured to modify the collections of external database queries at subsequent iterations of the execution of the complex procedural query.

6. The system of claim 1 wherein the set of database adaptors configured to optimize and refer the collections of queries to external databases is further configured to access the query cache to determine if results for at least one of the collections of external database queries is stored in the query cache.

7. The system of claim 1 wherein the database adaptors are configured to provide the results of the external database queries to the query cache, and to provide information indicative of the unresolved data.

8. The system of claim 1 further comprising an external memory, wherein the query cache is configured to be in communication with the external memory.

9. A method for complex procedural query execution, the method comprising:

a. executing an entire complex procedural query defined using a general-purpose functional programming language, detecting a soft failure, indicative that the execution of the query resulted in incomplete information, and noting any unresolved data which the query needs but does not have;

b. identifying sub-queries to be executed separately;

c. referring unresolved data needs to at least one database adaptor;

d. storing resulting responses in a query cache for a future execution; and

e. iteratively executing (a), (b), (c), and (d) using the resulting responses until no more soft failures occur,

wherein the complex procedural query is severable such that at least a first portion of the complex procedural query can proceed even if a second portion of the complex procedural query fails.

10. The method of claim 9 wherein the complex procedural query includes a query procedure and wherein the method further comprises identifying the query procedure by an object and by an argument of the procedure.

11. The method of claim 9 wherein the query language is maximally severable.

12. The method of claim 9 wherein iteratively re-executing (a), (b), (c), and (d) using the resulting responses includes generating database requests corresponding to the complex procedural query based on the resulting responses obtained in at least one earlier iteration of executing the query.

13. A system for processing complex procedural queries, the system comprising:

a query buffer processor for receiving a complex procedural query, including a plurality of sub-queries, for iterated execution, wherein the complex procedural query is expressed using a general-purpose functional programming language;

an external memory for storing non-persistent program data and procedures that can be routinely accessed in the course of query execution;

a query execution unit (QEU) processor in communication with the query buffer processor and the external memory, the QEU processor configured to iteratively execute the entire complex procedural query by executing the sub-queries of the complex procedural query and combining results of the sub-queries such that incomplete execution of one sub-query does not rule out execution of other independent sub-queries;

a device in communication with the QEU processor, the device configured to signal and respond to soft failures, which can terminate one sub-query of the complex procedural query while allowing other independent sub-queries to proceed;

a hardware query cache in communication with the QEU processor, the hardware query cache configured to store known query results for immediate retrieval without recourse to at least one external database, to return known query results, and to return a soft failure, indicative that the execution of the complex procedural query resulted in incomplete information, when results are not known without recourse to at least one external database; and

a plurality of external database adaptor processors in communication with the hardware query cache, the database adaptor processors configured to optimize a set of independent queries bundled together into a single package,

wherein the QEU processor is configured to execute a subsequent iteration of the entire complex procedural query, if a soft failure is returned from a previous iteration of the query, using results of the query obtained in at least one earlier iteration of the query execution until no further soft failures occur,

wherein the complex procedural query is severable such that at least a first portion of the complex procedural query can proceed even if a second portion of the complex procedural query fails.

14. The system of claim 13 wherein the device is configured to signal a requesting application that the query execution is complete when a query execution completes without any software failures.

15. The system of claim 14 wherein the QEU processor is configured to forward the results of the query execution to a requesting application when a query execution completes without any software failures.

16. The system of claim 13 wherein the system further comprises:

a query rewriter processor in communication with the query buffer, the query rewriter processor configured to receive the complex procedural query and to convert certain query language constructs into a form that the QEU processor can execute.

17. The system of claim 13 wherein the plurality of database adaptors are configured to provide the known query results to the hardware query cache, and to provide information indicative of the soft failures.

18. The system of claim 13 wherein the hardware query cache is further configured to be in communication with the external memory.

19. The system of claim 13 wherein the QEU processor is configured to be used with a query language that is repetitively innocuous.

20. The system of claim 13 wherein one or more of the query buffer processor, the external memory, the QEU processor, the device, the hardware query cache, and the plurality of external database adaptor processors are combined in a single hardware unit.