Method for efficient processing of multi-state attributes

• US 7,089,230 B2
• Filed: 06/07/2002
• Issued: 08/08/2006
• Est. Priority Date: 06/07/2002
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kathmann, Kevin James, Carlson, David Glenn
• Primary Examiner(s): Alam, Shahid
• Application Number:
  US10/164,767
• Publication Number:
  US 20030229620A1
• Time in Patent Office: 1,523 Days
• Field of Search: 707/2, 707/100, 707/200, 707/3, 707/10, 709/201, 709/208
• US Class Current: 1/1
• CPC Class Codes: G06F 16/24553 of query operations
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

Methods, systems and articles of manufacture of processing a multi-state attribute field query. One embodiment provides a method of processing a multi-state attribute field query, comprising instantiating a plurality of live objects; performing, by each live object, an attribute operation, wherein at least one attribute operation is a comparison operation associated with attributes of the query. The plurality of live objects access a global status storage area only when an operand of the comparison operation is null or error. In any case, execution control is passed from each live object to an adjacent live object.

Claims

1. A method of processing a database query that includes one or more multi-state attribute fields, comprising:

instantiating a plurality of live objects, wherein each live object includes a reference to a first operand and a second operand;

performing, by a first live object, an attribute operation, wherein at least one attribute operation is a comparison operation associated with attributes of the query;

performing the comparison operation by de-referencing the first and second operands and loading the de-referenced operands into registers without placing the de-referenced operands into an intermediate data structure;

if the comparison operation results in a null or error status, accessing, a global status storage area and recording the null or error status by placing a status value and a behavior value in the global status storage area; and

otherwise, if the comparison operation results in a valid result status, passing execution control from the first live object to an adjacent live object.

2. The method of claim 1, wherein execution control passes using call foliation.

3. The method of claim 1, wherein each comparison operation comprises a logic value and sub-tree height count allowing a previous comparison operation of the query to track a number of statuses in the global status storage area to be evaluated.

4. The method of claim 1, further comprising, in the event an attribute operand of the comparison operation is null or error, passing execution control to an adjacent live object via one of a TRUE branch and a FALSE branch.

5. The method of claim 1, wherein accessing the global status storage area comprises placing a Boolean logic operator value in the global status storage area.

6. The method of claim 1, wherein the global status storage area is a status stack for storing status information of comparison operations.

7. The method of claim 1, wherein the global status storage area preserves an order in which statuses are stored to the global status storage area.

8. The method of claim 1, further comprising:

if the comparison operation includes invalid state attribute operands, using non-outcome determinative input-output logic operator properties to structure execution flow circumventing unproductive branches and yielding intermediate results from a group of true and false;

whereby invalid intermediate results are pruned out rendering them ineffective in producing query results.

9. The method of claim 1, wherein the query is a structure query language (SQL) query.

10. The method of claim 1, wherein the comparison operation is one of a pair of comparison operations of a Boolean AND logic operator and if any operands of the comparison operation is an error or null, then driving execution flow to an adjacent object via a true branch in order to promote a FALSE state mapping.

11. The method of claim 1, wherein the comparison operation is one of a pair of comparison operations of a Boolean OR logic operator and if any operands of the comparison operation is an error or null, then driving execution flow to an adjacent object via a false branch in order to promote a TRUE state mapping.

12. A computer readable medium containing a program which, when executed, performs an operation for processing a database query that includes one or more multi-state attribute fields, the operation comprising:

instantiating a plurality of live objects, wherein each live object includes a reference to a first operand and a second operand;

performing, by a first live object, an attribute operation, wherein at least one attribute operation is a comparison operation associated with attributes of the query;

performing the comparison operation by de-referencing the first and second operands and loading the de-referenced operands into registers without placing the de-referenced operands into an intermediate data structure;

if the comparison operation results in a null or error status, accessing, a global status storage area and recording the null or error status by placing a status value and a behavior value in the global status storage area; and

otherwise, if the comparison operation results in a valid result status, passing execution control from the first live object to an adjacent live object.

13. The computer-readable medium of claim 12, wherein execution control passes using call foliation.

14. The computer-readable medium of claim 12, wherein each comparison operation comprises a logic value and sub-free height count allowing a previous comparison operation of the query to track a number of statuses in the global status storage area to be evaluated.

15. The computer-readable medium of claim 12, further comprising, in the event an attribute operand of the comparison operation is null or error, passing execution control to an adjacent live object via one of a TRUE branch and a FALSE branch.

16. The computer-readable medium of claim 12, wherein accessing the global status storage area comprises placing a Boolean logic operator value in the global status storage area.

17. The computer-readable medium of claim 12, wherein the global status storage area is a status stack for storing status information of comparison operations.

18. The computer-readable medium of claim 12, wherein the global status storage area preserves an order in which statuses are stored to the global status storage area.

19. The computer-readable medium of claim 12, further comprising:

if the comparison operation includes invalid state attribute operands, using non-outcome determinative input-output logic operator properties to structure execution flow circumventing unproductive branches and yielding intermediate results from a group of true and false;

whereby invalid intermediate results are pruned out rendering them ineffective in producing query results.

20. The computer-readable medium of claim 12, wherein the query is a structure query language (SQL) query.

21. The computer-readable medium of claim 12, wherein the comparison operation is one of a pair of comparison operations of a Boolean AND logic operator and if any operands of the comparison operation is an error or null, then driving execution flow to an adjacent object via a true branch in order to promote a FALSE state mapping.

22. The computer-readable medium of claim 12, wherein the comparison operation is one of a pair of comparison operations of a Boolean OR logic operator and if any operands of the comparison operation is an error or null, then driving execution flow to an adjacent object via a false branch in order to promote a TRUE state mapping.