Method and apparatus for efficiently executing built-in functions

• US 6,249,783 B1
• Filed: 12/17/1998
• Issued: 06/19/2001
• Est. Priority Date: 12/17/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Crone, Christopher J., Malone, Patrick M., Ruggles, Jeffrey R.
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): Mizrahi, Diane D.
• Application Number:
  US09/215,037
• Time in Patent Office: 915 Days
• Field of Search: 707/1, 707/2, 707/3, 707/4, 707/5, 707/102, 707/103, 707/104, 717/8, 714/38, 700/83, 703/203
• US Class Current: 1/1
• CPC Class Codes: G06F 16/24553 of query operations
• CPC Class Codes: G06F 16/24554 Unary operations; Data partitioning operations
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• 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 707/99935 Query augmenting and refining, e.g. inexact access
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing

Abstract

A method, apparatus and article of manufacture for computer implemented method of efficiently executing built-in functions is defined. Function modules are defined to process a single data type class and to process as many functions as possible before returning to the caller. Functions related to a query are each assigned a key, a type of code, to indicate the data type class to which the function belongs. The functions are then ordered so that a particular module scope can be held as long as possible. Further, data fields, another type of code containing optimization information, can be added to the functions to further enable the holding of module scope. Finally, the functions are executed at runtime. During execution, the database system looks ahead at upcoming functions in an attempt anticipate the next course of action by examining the keys and data fields. Various additional optimization techniques can then be used to enhance runtime performance.

Claims

1. A method of efficiently executing a query in a database system, the query having been parsed to obtain a related set of functions, the method comprising the steps of:

defining a set of function modules, wherein each function module is defined to process a single class of data types, thereby limiting a number of functions to be recognized by each function module; and

assigning each function in the set of functions a key, the key representing the class of data types to which each function belongs.

2. The method according to claim 1, further comprising the step of:

rearranging an order in which each function in the set of functions is executed to increase locality, thereby optimizing runtime performance.

3. The method according to claim 1, further comprising the step of:

executing each function in a presently called module, while examining the key of a subsequent function from the set of functions to determine a next course of action.

4. The method according to claim 1, wherein in said defining step, each of the function modules is further defined to process simple operations associated with the class of functions, thereby merging the simple operations with the associated class of functions into a single unit.

5. The method according to claim 3, wherein in the executing step, when the key indicates that the subsequent function is to be executed in the presently called module, the subsequent function is executed prior to issuing a return, thereby further optimizing runtime performance.

6. The method according to claim 5, further comprising the step of:

prior to the executing step, assigning a code to each function, the code indicating whether execution of the subsequent function requires a call forward to a subsequent module or a fall back to a previous module.

7. The method according to claim 6, wherein the executing step further comprises examining the code and, wherein when the key indicates that the subsequent function is not to be executed in the presently called module, and the code indicates that execution of the subsequent function requires a call forward to the subsequent module, the subsequent module is called and the subsequent function is executed prior to issuing a return.

8. The method according to claim 7, wherein in the executing step, when the key indicates that the subsequent function is not to be executed in the presently called module, and the code indicates that execution of the subsequent function requires a fall back to the previous module, the previous module is returned to and the subsequent function is executed prior to issuing a return.

9. The method according to claim 3, further comprising the step of:

prior to the executing step, sorting each function and assigning each function a code indicating whether execution of each function requires a call forward to a subsequent module, fall back to a previous module or loop to the presently called module;

wherein the executing step further comprises examining the code of the subsequent function and executing one of the call forward, fall back and loop based on the code, to execute the subsequent function.

10. The method according to claim 2, wherein in the rearranging step, the locality is increased by ordering together each function having the same key, while honoring dependencies between the functions.

11. An apparatus for efficiently executing a query in a database system, the query having been parsed to obtain a related set of functions, the apparatus comprising:

a computer having a data storage device connected thereto, wherein the data storage device stored the database system; and

one or more computer programs performed by the computer for;

defining a set of function modules, wherein each function module is defined to process a single class of data types, thereby limiting a number of functions to be recognized by each function module; and

assigning each function in the set of functions a key, the key representing the class of data types to which each function belongs.

12. The apparatus according to claim 11, wherein the one or more computer programs performed by the computer further rearranges an order in which each function in the set of functions is executed to increase locality, thereby optimizing runtime performance.

13. The apparatus according to claim 11, wherein the one or more computer programs performed by the computer further executes each function in a presently called module, while examining the key of a subsequent function from the set of functions to determine a next course of action.

14. The apparatus according to claim 11, wherein the one or more computer programs performed by the computer further defines each function to process simple operations associated with the class of functions, thereby merging the simple operations with the associated class of functions into a single unit.

15. The apparatus according to claim 11, wherein the one or more computer programs performed by the computer, further executes the subsequent function prior to issuing a return when the key indicates that the subsequent function is to be executed in the presently called module, thereby further optimizing runtime performance.

16. The apparatus according to claim 15, wherein the one or more computer programs performed by the computer further assigns a code to each function prior to executing, the code indicating whether execution of the subsequent function requires a call forward to a subsequent module or a fall back to a previous module.

17. The apparatus according to claim 16, wherein the one or more computer programs performed by the computer further examines the code during executing and, wherein when the key indicates that the subsequent function is not to be executed in the presently called module, and the code indicates that execution of the subsequent function requires a call forward to the subsequent module, the subsequent module is called and the subsequent function is executed prior to issuing a return.

18. The apparatus according to claim 17, wherein the one or more computer programs performed by the computer, during executing, further returns to the previous module and executes the subsequent function prior to issuing a return, when the key indicates that the subsequent function is not to be executed in the presently called module, and the code indicates that execution of the subsequent function requires a fall back to the previous module.

19. The apparatus according to claim 13, wherein the one or more computer programs performed by the computer further sorts each function and assigns each function a code, prior to executing, indicating whether execution of each function requires a call forward to a subsequent module, fall back to a previous module or loop to the presently called module;

further wherein during executing, the one or more computer programs performed by the computer examines the code of the subsequent function and executes one of the call forward, fall back and loop based on the code, to execute the subsequent function.

20. The apparatus according to claim 12, wherein the one or more computer programs performed by the computer further increases the locality, during rearranging, by ordering together each function having the same key, while honoring dependencies between the functions.

21. An article of manufacture comprising a program storage device readable by a computer and tangibly embodying one or more programs of instructions executable by the computer to perform method steps for efficiently executing a query in a database system, the query having been parsed to obtain a related set of functions, the computer having a data storage device coupled thereto for storing the database system, the method comprising the steps of:

defining a set of function modules, wherein each function module is defined to process a single class of data types, thereby limiting a number of functions to be recognized by each function module; and

assigning each function in the set of functions a key, the key representing the class of data types to which each function belongs.

22. The article of manufacture according to claim 21, further comprising the step of:

rearranging an order in which each function in the set of functions is executed to increase locality, thereby optimizing runtime performance.

23. The article of manufacture according to claim 21, further comprising the step of:

executing each function in a presently called module, while examining the key of a subsequent function from the set of functions to determine a next course of action.

24. The article of manufacture according to claim 21, wherein in said defining step, each of the function modules is further defined to process simple operations associated with the class of functions, thereby merging the simple operations with the associated class of functions into a single unit.

25. The article of manufacture according to claim 23, wherein in the executing step, when the key indicates that the subsequent function is to be executed in the presently called module, the subsequent function is executed prior to issuing a return, thereby further optimizing runtime performance.

26. The article of manufacture according to claim 25, further comprising the step of:

prior to the executing step, assigning a code to each function, the code indicating whether execution of the subsequent function requires a call forward to a subsequent module or a fall back to a previous module.

27. The article of manufacture according to claim 26, wherein the executing step further comprises examining the code and, wherein when the key indicates that the subsequent function is not to be executed in the presently called module, and the code indicates that execution of the subsequent function requires a call forward to the subsequent module, the subsequent module is called and the subsequent function is executed prior to issuing a return.

28. The article of manufacture according to claim 27, wherein in the executing step, when the key indicates that the subsequent function is not to be executed in the presently called module, and the code indicates that execution of the subsequent function requires a fall back to the previous module, the previous module is returned to and the subsequent function is executed prior to issuing a return.

29. The article of manufacture according to claim 23, further comprising the step of:

prior to the executing step, sorting each function and assigning each function a code indicating whether execution of each function requires a call forward to a subsequent module, fall back to a previous module or loop to the presently called module;

wherein the executing step further comprises examining the code of the subsequent function and executing one of the call forward, fall back and loop based on the code, to execute the subsequent function.

30. The article of manufacture according to claim 22, wherein in the rearranging step, the locality is increased by ordering together each function having the same key, while honoring dependencies between the functions.