Apparatus and method for using a predefined database operation as a data source for a different database operation

• US 7,213,014 B2
• Filed: 03/27/2003
• Issued: 05/01/2007
• Est. Priority Date: 03/27/2003
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Dettinger, Richard Dean, La Rocca, Jennifer Lynn, Stevens, Rick Joseph
• Primary Examiner(s): Wong; Don
• Assistant Examiner(s): FILIPCZYK, MARCIN R
• Application Number:
  US10/401,291
• Publication Number:
  US 20040193567A1
• Time in Patent Office: 1,496 Days
• Field of Search: 707 1- 10, 707/104.1, 707/200, 707/203, 707/100
• US Class Current: 1/1
• CPC Class Codes: G06F 16/24526 Internal representations for queries
• CPC Class Codes: G06F 16/24534 Query rewriting; Transformation
• CPC Class Codes: G06F 16/284 Relational databases
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99935 Query augmenting and refining, e.g. inexact access

Abstract

A database operation mechanism includes the capability of specifying a predefined database operation as a source of data for a different database operation. When the different database operation needs to be performed, the database operation mechanism determines whether the different database operation can use a predefined database operation as a data source. If so, the predefined database operation is specified as the source of data for the different database operation. If the different database operation cannot use a predefined database operation as a data source, the database operation mechanism determines whether the different database operation can use a modified form of a predefined database operation as a data source. If so, the different database operation may use the modified predefined database operation as a source of data. If the different database operation cannot use a predefined database operation or a modified form of a predefined database operation as a data source, a different database operation is generated and executed.

Claims

1. An apparatus comprising:

(A) at least one processor;

(B) a memory coupled to the at least one processor;

(C) a database residing in the memory; and

(D) a database operation mechanism residing in the memory and providing instructions for the at least one processor to perform the steps of;

(D1) identifying a predefined database operation and determining whether the predefined database operation provides a data source for a different database operation corresponding to a different database statement, and where the predefined database operation provides a data source, specifying the predefined database operation as a data source for the different database operation,

wherein the predefined database operation provides the data source for the different database operation when executing the predefined database operation returns a result set that includes data needed by the different database operation such that the result set provides the data source for the different database operation;

(D2) where the predefined database operation does not provide a data source for the different database operation, determining whether the predefined database operation is modifiable to serve as a data source for the different database operation;

(D3) where the predefined database operation is modifiable to serve as a data source for the different database operation and such modification is desirable based on at least one predetermined criterion, performing the steps of;

(D3A) modifying the predefined database operation; and

(D3B) specifying the modified database operation as the data source for the different database operation;

(D4) where the predefined database operation is not modifiable to serve as a data source for the different database operation or if such modification is not desirable based on the at least one predetermined criterion, generating an executable database operation from the different database statement and executing the executable database operation.

2. The apparatus of claim 1 wherein the predefined database operation is modifiable to serve as the data source for the different database operation if executing the modified database operation returns a result set that includes data needed by the different database operation.

3. A computer-implemented method for processing a new database statement, the method comprising the steps of:

(1) identifying a predefined database operation and determining whether the predefined database operation provides a data source for a new database operation that corresponds to the new database statement, and where the predefined database operation provides a data source, specifying the predefined database operation as a data source for the new database operation, wherein the predefined database operation provides the data source for the different database operation when executing the predefined database operation returns a result set that includes data needed by the different database operation such that the result set provides the data source for the different database operation;

(2) where the predefined database operation does not provide a data source for the new database operation, determining whether the predefined database operation is modifiable to serve as a data source for the new database operation;

(3) where the predefined database operation is modifiable to serve as a data source for the new database operation and such modification is desirable based on at least one predetermined criterion, performing the steps of;

(3A) modifying the predefined database operation; and

(3B) specifying the modified database operation as the data source for the new database operation;

(4) where the predefined database operation is not modifiable to serve as a data source for the new database operation or if such modification is not desirable based on the at least one predetermined criterion, generating a new executable database operation from the new database operation and executing the new executable database operation.

4. The method of claim 3 wherein the predefined database operation is modifiable to serve as the data source for the new database operation if executing the modified database operation returns a result set that includes data needed by the new database operation.

5. A program product comprising:

(A) a database operation mechanism that performs the steps of;

(A1) identifying a predefined database operation and determining whether the predefined database operation provides a data source for a different database operation, and where the predefined database operation provides a data source, specifying the predefined database operation as a data source for the different database operation, wherein the predefined database operation provides the data source for the different database operation if executing the predefined database operation returns a result set that includes data needed by the different database operation such that the result set provides the data source for the different database operation;

(A2) where the predefined database operation does not provide a data source for the different database operation, determining whether the predefined database operation is modifiable to serve as a data source for the different database operation;

(A3) where the predefined database operation is modifiable to serve as a data source for the different database operation and such modification is desirable based on at least one predetermined criterion, performing the steps of;

(A3A) modifying the predefined database operation; and

(A3B) specifying the modified database operation as the data source for the different database operation;

(A4) where the predefined database operation is not modifiable to serve as a data source for the different database operation or if such modification is not desirable based on the at least one predetermined criterion, generating an executable database operation from the different database operation and executing the executable database operation; and

(B) computer-readable medium in which computer instructions are stored, which instructions, when read by a computer, cause the computer to perform the steps of the database operation mechanism.

6. The program product of claim 5 wherein the predefined database operation is modifiable to serve as the data source for the different database operation if executing the modified database operation returns a result set that includes data needed by the different database operation.