Computer-readable medium to multiplex multiple application server requests over a single database connection

• US 7,933,948 B2
• Filed: 06/30/2008
• Issued: 04/26/2011
• Est. Priority Date: 12/04/2003
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lam, Michelle D., Bireley, William R., Bird, Paul M., Sun, Frankie K., Fuller, Georgia C., Dong, Margaret A., Cotner, Curt L., Pickel, James W., Dang, Tammie
• Primary Examiner(s): SHIN, KYUNG H
• Application Number:
  US12/164,920
• Publication Number:
  US 20080270609A1
• Time in Patent Office: 1,030 Days
• Field of Search: 709/217, 709/223, 709/216, 709/232, 709/225
• US Class Current: 709/201
• 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 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 non-transitory computer readable medium containing program instructions for controlling a computing device to avoid a section collision for application server requests over a single database connection between a database server and an application server, wherein execution of program instructions by one or more processors of a computer system causes the one or more processors to carry out the steps of:

(a) receiving a first statement assigned a first command source identifier by the database server from a first application source over a single database connection, the first command source identifier uniquely identifying an application source to the first statement;

(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, the second command source identifier uniquely identifying an application source 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 medium of claim 1, wherein the first and second command source identifiers are assigned by the application server.

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

4. The medium of claim 1, wherein the first statement assigned the first command source identifier and the second statement assigned the second command source identifier are combined into 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.

5. The medium 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 medium 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 cursor.

7. The medium of claim 6, wherein the executing instruction (c) further 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 query identifier and second query identifiers to the application server.

8. A non-transitory computer readable medium storing instructions containing program instructions for controlling a computing device to avoid a section collision for application server requests over a single database connection between a database server and an application server, wherein execution of program instructions by one or more processors of a computer system causes the one or more processors to carry out the steps of:

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

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

(c) assigning the first instance a first query identifier, the first query identifier uniquely identifies the first instance of the open cursor;

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

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

(f) assigning the second instance a second query identifier, the second query identifier uniquely identifies the second instance of the open cursor.

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

10. The medium of claim 8, further comprising instructions for:

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

11. The medium of claim 8, further comprising instructions for:

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

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

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

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