Method and system for using dynamically generated code to perform index record retrieval in certain circumstances in a relational database manager

• US 6,353,820 B1
• Filed: 09/29/1999
• Issued: 03/05/2002
• Est. Priority Date: 09/29/1999
• Status: Expired due to Term

• Current Assignee: Bull HN Information Systems Incorporated (Atos SE)
• Original Assignee: Bull HN Information Systems Incorporated (Atos SE)
• Inventors: Kneisel, Todd, Edwards, David S.
• Primary Examiner(s): Alam, Hosain T.
• Assistant Examiner(s): ALAM, SHAHID AL
• Application Number:
  US09/408,986
• Time in Patent Office: 888 Days
• Field of Search: 707/1, 707/2, 707/3, 707/4, 707/5, 707/10, 707/101, 707/102, 707/103.R, 707/104.1, 707/206, 709/201, 709/215, 709/216, 711/4, 711/100, 711/112, 711/150, 711/171, 711/200, 711/202, 711/216, 711/217, 714/11, 705/35
• US Class Current: 707/696
• CPC Class Codes: G06F 16/2272 Management thereof
• CPC Class Codes: Y10S 707/954 Relational
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• 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

Abstract

A system and method that enhances the index processing performance of a multi-layer relational database manager by expanding the code generation component layer of the database manager to include an index processing performance enhancing subroutine designed to execute functions performed by lower component layers substantially faster than if the functions were executed by such lower component layers. The subroutine includes logic for establishing the conditions under which the particular subroutine is invoked during the execution of a SQL request. The output code generated to execute a specific SQL query, including calls to the index processing subroutine in place of normally included calls to the lower component layer. This enables the generated code to perform lower component layer functions with specialized code designed to increase performance.

Claims

1. A method for enhancing the performance of a data manager that manages a relational database, the manager having a number of operatively coupled component layers for performing functions required for accessing the relational database file records in response to user query statements, the number of component layers including a first component layer for generating output code used in executing the query statement in response to input representing an optimized form of the query statement and a number of lower component layers, the method comprising the steps of:

(a) adding an index processing performance enhancing subroutine to a subroutine library included within the first component layer, the index processing performance enhancing subroutine being designed to execute index processing functions performed by lower component layers substantially faster than if the function were executed by the lower component layers, and including code for determining conditions under which the particular subroutine is to be invoked during query execution time;

(b) including calls in the generated output code to the index processing enhancing subroutine in place of normally included calls to the lower component layers for inserting the index processing enhancing subroutine into the generated code; and

,

(c) including logic within the index processing enhancing subroutine for determining if the index processing enhancing subroutine can be reliably invoked based on a predetermined set of conditions.

2. The method of claim 1 wherein the calls included in the generated output code are in place of normally included calls to a prior index processing subroutine that unconditionally invoked lower component layers.

3. The method of claim 1 wherein the predetermined set of conditions indicate that there were no changes in index currency and in a fine level index used for retrieving the database file records.

4. The method of claim 3 wherein the fine level index contains entries that are lightly packed adjacent to one another in sorted order enabling the logic in the index processing enhancing subroutine to walk through the fine level index taking entries right out from under control of one of the number of lower component layers as search next requests are being processed.

5. The method of claim 4 wherein the first component layer includes a code generation component and the one of the lower component layers includes a relational file manager (RFM) component having a library for storing a number of routines for performing the lower layer index functions.

6. The method of claim 5 wherein the number of lower component layers further includes a third lower component layer operatively coupled to the first component layer, to the second lower component layer and to the relational database for executing input/output operations required for executing the query statement.

7. The method of claim 6 wherein in step (c), the first component layer invokes the index processing performance subroutine to call conditionally, the third lower component layer function based on the setting of a result processing indicator.

8. The method of claim 7 wherein the third lower component layer includes an input/output controller component that operatively couples to the relational database.

9. The method of claim 1 wherein the index processing enhancing subroutine is coded for performing a number of different index state tests for determining the set of predetermined conditions.

10. A data manager for managing a relational database, the manager having a number of operatively coupled component layers for performing functions required for accessing database file records of the relational database in response to user query statements, the number of component layers including a first component layer for generating output code used in executing the query statement in response to input representing an optimized form of the query statement and a number of lower component layers operatively coupled to the first component layer, to each other and to the relational database, the lower component layers, the first component layer further including:

(a) a subroutine library including an index processing performance enhancing subroutine designed to execute functions performed by lower component layers substantially faster than if the functions were executed by the lower component layers, the index processing subroutine including coded logic for determining conditions under which the subroutine is to be executed;

(b) the generated output code being stored in memory and including calls to the index processing subroutine stored in the subroutine library in place of normally included calls to a prior index processing subroutine that unconditionally invoked lower component layers; and

,

(c) the generated output code when accessed from memory during execution of the query invoking the index processing subroutine to perform the lower layer functions.

11. The data manager of claim 10 wherein the particular conditions indicate there were no changes in index currency and in a fine level index used in retrieving the database file records.

12. The data manager of claim 11 wherein the fine level index contains entries that are lightly packed adjacent to one another in sorted order enabling the coded logic to walk through the fine coded level index taking entries out from under control of the second lower component layer.

13. The data manager of claim 12 wherein the first component layer includes a code generation component and the second lower component layer includes a relational file manager (RFM) component having a library for storing a number of routines for performing the index processing functions utilizing the fine level index.

14. The data manager of claim 13 wherein the number of lower component layers further includes a third lower component layer operatively coupled to the first component layer, to the second lower component layer and to the relational database for executing input/output operations required for executing the query statement.

15. The data manager of claim 14 wherein in the first component layer during the execution of the query invokes the index processing subroutine to invoke the third lower component layer function when a result processing indicator has been set.

16. The data manager of claim 15 wherein the third lower component layer includes an input/output controller component that operatively couples to the relational database.

17. An RDMS program product including a data manager for managing a relational database stored on a media as groups of program instructions, the instructions corresponding to a number of operatively coupled component layers for performing functions required for accessing database file records of the relational database in response to user query statements, the number of component layers including a first component layer for generating code used in executing the query statement in response to input representing an optimized form of the query statement and a number of lower component layers operatively coupled to the first component layer, to each other and to the relational database, the first component layer further including:

(a) a first group of instructions corresponding to a subroutine library that includes an index processing performance enhancing subroutine designed to execute functions performed by lower component layers substantially faster than if the functions were executed by the number of lower component layers, the index processing performance enhancing subroutine including code containing instructions for determining conditions under which the particular subroutine is to be executed;

(b) a second group of instructions corresponding to a code generation component for providing output code containing calls to the index processing performance enhancing subroutine in place of normally included calls to lower component layers that inserts the index processing subroutine into the output code; and

,

(c) another group of instructions included within the index processing subroutine for causing the execution of the index processing subroutine to perform the second lower layer functions based on a particular set of conditions resulting in increased performance.

18. A memory for storing a data manager for accessing data records of a relational database during the execution of a query, the memory comprising:

(a) first component layer for generating code used in executing the query statement in response to input representing an optimized form of the query statement and a number of lower component layers operatively coupled to the first component layer, to each other and to the relational database, the lower component layers, the first component layer contained in the memory further including;

(1) a subroutine library including an index processing performance enhancing subroutine designed to execute functions performed by lower component layers substantially faster than if the functions were executed by the lower component layers, the row retrieval performance enhancing subroutine including code for determining conditions under which the particular subroutine is to be invoked during index processing;

(2) generated output code including calls to the index processing performance enhancing subroutine in place of normally included calls to the lower component layers for incorporating the index processing subroutine into the generated output code for execution of the query being processed; and

,

(3) a memory area being assigned for storing the output code, the output code accessed during execution of the query causing the index processing subroutine to be executed for performing the lower layer functions as a function of a particular set of conditions so as to result in increased performance.