Method, system and mechanism to multiplex multiple application server requests over a single database connection

• US 20050144276A1
• Filed: 12/04/2003
• Published: 06/30/2005
• Est. Priority Date: 12/04/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cotner, Curt L., Pickel, James W., Dang, Tammie, Lam, Michelle D., Bireley, William R., Bird, Paul M., Sun, Frankie K., Fuller, Georgia C., Dong, Margaret A.
• Granted Patent: US 7,433,950 B2
• Time in Patent Office: Days
• US Class Current: 709/225
• CPC Class Codes: G06F 16/2308 Concurrency control transaction processing G06F9/466
• CPC Class Codes: G06F 16/24532 of parallel queries
• CPC Class Codes: G06F 16/252 between a Database Management System and a front-end application
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

In a method and system for avoiding section collision for application server requests over a single database connection, the database server assigns query identifiers to each instance of the same cursor opened for the same processing level within an application, allowing multiple instances of the same cursor to be processed in parallel without section collision. The application server assigns a command source identifier to each statement sent over a single database connection to uniquely identify the application source of the statement. This applies for multiples of the same statement sent by different application sources within the same application, for a single statement containing multiple application sources, and for multiple statements from different applications multiplexed over a single database connection. These statements can be processed separately from and in parallel with the each other without section collision.

Claims

1. A method for avoiding section collision for application server requests over a single database connection, the method comprising:

(a) receiving a first statement assigned a first command source identifier by a database server from a first application source over a single database connection between the database server and an application server;

(b) receiving a second statement assigned a second command source identifier by the database server from a second application source over the single database connection, wherein the first statement is substantially identical to the second statement; and

(c) executing the first statement assigned a first command source identifier separately from and in parallel with the second statement assigned the second command source without section collision.

2. The method of claim 1, wherein the first and second command source identifiers are assigned by the application server.

3. The method of claim 1, wherein the first application source and the second application source are different application sources within a same application.

4. The method of claim 1, wherein the first statement assigned the first command source identifier and the second statement assigned the second command source identifier is a single statement containing the first and second application sources, wherein a portion of the single statement pertaining to the first application source is assigned the first command source identifier, and wherein a portion of the single statement pertaining to the second application source is assigned the second command source identifier.

5. The method of claim 1, wherein the first application source is within a first application and the second application source is within a second application.

6. The method of claim 1, wherein the first statement assigned the first command source identifier is a statement to open a cursor and wherein the second statement assigned the second command source identifier is a statement to open the same cursor.

7. The method of claim 6, wherein the executing (c) comprises:

(c1) creating a first instance of the cursor in response to the first statement assigned the first command source identifier;

(c2) assigning a first query identifier to the first instance of the cursor by the database server;

(c3) creating a second instance of the cursor in response to the second statement assigned the second command source identifier;

(c4) assigning a second query identifier to the second instance of the cursor by the database server; and

(c5) returning the first and second query identifiers to the application server.

8. A method for avoiding section collision for application server requests over a single database connection, the method comprising:

(a) receiving a first statement to open a cursor by an database server over a single database connection between the database server and an application server;

(b) creating a first instance of the cursor in response to the first statement;

(c) assigning the first instance a first query identifier;

(d) receiving a second statement to open the same cursor by the database server over the single database connection before the first instance of the cursor closes;

(e) creating a second instance of the cursor in response to the second statement; and

(f) assigning the second instance a second query identifier.

9. The method of claim 8, wherein the first and second query identifiers are assigned by the database server.

10. The method of claim 8, further comprising:

(g) processing the first instance of the cursor separately from and in parallel with the second instance of the cursor.

11. The method of claim 8, further comprising:

(g) returning the first and second query identifiers to the application server.

12. The method of claim 11, wherein subsequent statements received by the database server for the first instance of the cursor comprises the first query identifier.

13. The method of claim 11, wherein subsequent statements received by the database server for the second instance of the cursor comprises the second query identifier.

14. The method of claim 8, wherein the first statement is from a first application source and is assigned a first command source identifier, wherein the second statement is from a second application source and is assigned a second command source identifier.

15. A computer readable medium with program instructions for avoiding section collision for application server requests over a single database connection, comprising the instructions for:

(a) receiving a first statement assigned a first command source identifier by a database server from a first application source over a single database connection between the database server and an application server;

(b) receiving a second statement assigned a second command source identifier by the database server from a second application source over the single database connection, wherein the first statement is substantially identical to the second statement; and

(c) executing the first statement assigned a first command source identifier separately from and in parallel with the second statement assigned the second command source without section collision.

16. The medium of claim 15, wherein the first and second command source identifiers are assigned by the application server.

17. The medium of claim 15, wherein the first application source and the second application source are different application sources within a same application.

18. The medium of claim 15, wherein the first statement assigned the first command source identifier and the second statement assigned the second command source identifier is a single statement involving the first and second application sources, wherein a portion of the single statement pertaining to the first application source is assigned the first command source identifier, and wherein a portion of the single statement pertaining to the second application source is assigned the second command source identifier.

19. The medium of claim 15, wherein the first application source is within a first application and the second application source is within a second application.

20. The medium of claim 15, wherein the first statement assigned the first command source identifier is a statement to open a cursor and wherein the second statement assigned the second command source identifier is a statement to open the same cursor.

21. The medium of claim 20, wherein the executing instruction (c) comprises instructions for:

(c1) creating a first instance of the cursor in response to the first statement assigned the first command source identifier;

(c2) assigning a first query identifier to the first instance of the cursor by the database server;

(c3) creating a second instance of the cursor in response to the second statement assigned the second command source identifier;

(c4) assigning a second query identifier to the second instance of the cursor by the database server; and

(c5) returning the first and second query identifiers to the application server.

22. A computer readable medium with program instructions for avoiding section collision for application server requests over a single database connection, comprising the instructions for:

(a) receiving a first statement to open a cursor by an database server over a single database connection between the database server and an application server;

(b) creating a first instance of the cursor in response to the first statement;

(c) assigning the first instance a first query identifier;

(d) receiving a second statement to open the same cursor by the database server over the single database connection before the first instance of the cursor closes;

(e) creating a second instance of the cursor in response to the second statement; and

(f) assigning the second instance a second query identifier.

23. The medium of claim 22, wherein the first and second query identifiers are assigned by the database server.

24. The medium of claim 22, further comprising instructions for:

(g) processing the first instance of the cursor separately from and in parallel with the second instance of the cursor.

25. The medium of claim 22, further comprising instructions for:

(g) returning the first and second query identifiers to the application server.

26. The medium of claim 25, wherein subsequent statements received by the database server for the first instance of the cursor comprises the first query identifier.

27. The medium of claim 25, wherein subsequent statements received by the database server for the second instance of the cursor comprises the second query identifier.

28. The medium of claim 22, wherein the first statement is from a first application source and is assigned a first command source identifier, wherein the second statement is from a second application source and is assigned a second command source identifier.