Apparatus and method for using a predefined database operation as a data source for a different database operation

• US 20040193567A1
• Filed: 03/27/2003
• Published: 09/30/2004
• Est. Priority Date: 03/27/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Dettinger, Richard Dean, La Rocca, Jennifer Lynn, Stevens, Rick Joseph
• Granted Patent: US 7,213,014 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/24526 Internal representations for queries
• CPC Class Codes: G06F 16/24534 Query rewriting; Transformation
• CPC Class Codes: G06F 16/284 Relational databases
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99935 Query augmenting and refining, e.g. inexact access

Abstract

A database operation mechanism includes the capability of specifying a predefined database operation as a source of data for a different database operation. When the different database operation needs to be performed, the database operation mechanism determines whether the different database operation can use a predefined database operation as a data source. If so, the predefined database operation is specified as the source of data for the different database operation. If the different database operation cannot use a predefined database operation as a data source, the database operation mechanism determines whether the different database operation can use a modified form of a predefined database operation as a data source. If so, the different database operation may use the modified predefined database operation as a source of data. If the different database operation cannot use a predefined database operation or a modified form of a predefined database operation as a data source, a different database operation is generated and executed.

Claims

1. An apparatus comprising:

at least one processor;

a memory coupled to the at least one processor;

a database residing in the memory; and

a database operation mechanism residing in the memory and executed by the at least one processor, the database operation mechanism specifying a predefined database operation as a data source for a different database operation.

2. The apparatus of claim 1 wherein the predefined database operation may serve as the data source for the different database operation if executing the predefined database operation returns a result set that includes data needed by the different database operation.

3. An apparatus comprising:

(A) at least one processor;

(B) a memory coupled to the at least one processor;

(C) a database residing in the memory; and

(D) a database operation mechanism residing in the memory and executed by the at least one processor, the database operation mechanism performing the steps of;

(D1) determining whether a predefined database operation exists that may serve as a data source for a different database operation corresponding to a different database statement, and if so, specifying the predefined database operation as a data source for the different database operation;

(D2) if no predefined database operation exists that may serve as a data source for the different database operation, determining whether a predefined database operation may be modified to serve as a data source for the different database operation;

(D3) if a predefined database operation may be modified to serve as a data source for the different database operation and such modification is desirable based on at least one predetermined criterion, performing the steps of;

(D3A) modifying the predefined database operation; and

(D3B) specifying the modified database operation as the data source for the different database operation;

(D4) if no predefined database operation may be modified to serve as a data source for the different database operation or if such modification is not desirable based on the at least one predetermined criterion, generating an executable database operation from the different database statement and executing the executable database operation.

4. The apparatus of claim 3 wherein the predefined database operation may serve as the data source for the different database operation if executing the predefined database operation returns a result set that includes data needed by the different database operation.

5. The apparatus of claim 3 wherein the predefined database operation may be modified to serve as the data source for the different database operation if executing the modified database operation returns a result set that includes data needed by the different database operation.

6. A computer-implemented method for processing a new database statement, the method comprising the steps of:

identifying a predefined database operation that may serve as a data source for the new database statement; and

specifying the predefined database operation as the data source for the new database statement.

7. The method of claim 6 wherein the predefined database operation may serve as the data source for the new database statement if executing the predefined database operation returns a result set that includes data needed by the new database operation.

8. A computer-implemented method for processing a new database statement, the method comprising the steps of:

(1) determining whether a predefined database operation exists that may serve as a data source for a new database operation that corresponds to the new database statement, and if so, specifying the predefined database operation as a data source for the new database operation;

(2) if no predefined database operation exists that may serve as a data source for the new database operation, determining whether a predefined database operation may be modified to serve as a data source for the new database operation;

(3) if a predefined database operation may be modified to serve as a data source for the new database operation and such modification is desirable based on at least one predetermined criterion, performing the steps of;

(3A) modifying the predefined database operation; and

(3B) specifying the modified database operation as the data source for the new database operation;

(4) if no predefined database operation may be modified to serve as a data source for the new database operation or if such modification is not desirable based on the at least one predetermined criterion, generating a new executable database operation from the new database operation and executing the new executable database operation.

9. The method of claim 8 wherein the predefined database operation may serve as the data source for the new database operation if executing the predefined database operation returns a result set that includes data needed by the new database operation.

10. The method of claim 8 wherein the predefined database operation may be modified to serve as the data source for the new database operation if executing the modified database operation returns a result set that includes data needed by the new database operation.

11. A program product comprising:

(A) a database operation mechanism that specifies a predefined database operation as a data source for a different database operation; and

(B) computer-readable signal bearing media bearing the database operation mechanism.

12. The program product of claim 11 wherein the computer-readable signal bearing media comprises recordable media.

13. The program product of claim 11 wherein the computer-readable signal bearing media comprises transmission media.

14. The program product of claim 11 wherein the predefined database operation may serve as the data source for the different database operation if executing the predefined database operation returns a result set that includes data needed by the different database operation.

15. A program product comprising:

(A) a database operation mechanism that performs the steps of;

(A1) determining whether a predefined database operation exists that may serve as a data source for a different database operation, and if so, specifying the predefined database operation as a data source for the different database operation;

(A2) if no predefined database operation exists that may serve as a data source for the different database operation, determining whether a predefined database operation may be modified to serve as a data source for the different database operation;

(A3) if a predefined database operation may be modified to serve as a data source for the different database operation and such modification is desirable based on at least one predetermined criterion, performing the steps of;

(A3A) modifying the predefined database operation; and

(A3B) specifying the modified database operation as the data source for the different database operation;

(A4) if no predefined database operation may be modified to serve as a data source for the different database operation or if such modification is not desirable based on the at least one predetermined criterion, generating an executable database operation from the different database operation and executing the executable database operation; and

(B) computer-readable signal bearing media bearing the database operation mechanism.

16. The program product of claim 15 wherein the computer-readable signal bearing media comprises recordable media.

17. The program product of claim 15 wherein the computer-readable signal bearing media comprises transmission media.

18. The program product of claim 15 wherein the predefined database operation may serve as the data source for the different database operation if executing the predefined database operation returns a result set that includes data needed by the different database operation.

19. The program product of claim 15 wherein the predefined database operation may be modified to serve as the data source for the different database operation if executing the modified database operation returns a result set that includes data needed by the different database operation.