System, method and computer program product for positioned update support

• US 5,987,465 A
• Filed: 09/25/1997
• Issued: 11/16/1999
• Est. Priority Date: 09/29/1994
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wang, Yun, Kleewein, James C., Lin, Eileen T.
• Primary Examiner(s): HOMERE, JEAN RAYMOND
• Application Number:
  US08/937,792
• Time in Patent Office: 782 Days
• Field of Search: 707/4, 707/10, 707/102, 395/200.31, 395/200.47, 395/200.53
• US Class Current: 1/1
• CPC Class Codes: G06F 16/256 in federated or virtual databases
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99939 Privileged access
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A system, method and computer program product for providing a common interface to a plurality of heterogeneous database management systems, wherein date associated with a client is distributed among the plurality of hetergeneous database management systems. The system simulates support of positioned update actions in any of the heterogeneous database management systems which does not support positioned update actions.

Claims

1. A method for proving a common interface for performing update actions in a plurality of heterogeneous database management systems, wherein data associated with a client is distributed among said plurality of heterogeneous database management systems, comprising the steps of:

(a) simulating support of positioned update actions in any of said heterogeneous database management systems which does not support positioned update actions, by;

(1) accessing metadata that identifies at least one primary key defined for a table;

(2) using the primary keys to obtain record identification information that uniquely identifies a record being modified by a positioned update action, wherein said positioned update action updates a record at a current position of a specified cursor; and

(3) requesting that said target database management system modify a record identified by said record identification information.

2. The method of claim 1, further comprising the step of determining whether the information obtained in said step (2) uniquely identifies a record.

3. A system for providing a common interface for performing update actions in a plurality of heterogeneous database management systems, wherein data associated with a client is distributed among said plurality of heterogeneous database management systems, comprising:

means for simulating support of positioned update actions in any of said heterogeneous database management systems which does not support positioned update actions, including;

means for accessing metadata that identifies at least one primary key defined for a table;

means for using the primary keys to obtaining record identification information that uniquely identifies a record being modified by a positioned update action, wherein said positioned update action updates a record at a current position of a specified cursor; and

means for requesting that said target database management system modify a record identified by said record identification information.

4. The system of claim 3, further comprising means for determining whether the information obtained by said means for obtaining uniquely identifies a record.

5. A computer program product for use with a computer system, said computer program product comprising:

a computer usable medium having computer readable program code means embodied in said medium for causing the computer system to provide a common interface for performing update actions in a plurality of heterogeneous database management systems, wherein data associated with a client is distributed among said plurality of heterogeneous database management systems, said computer readable program code means comprising;

first computer readable program code means for simulating support of positioned update actions in any of said heterogeneous database management systems which does not support positioned update actions, including;

second computer readable program code means for enabling the computer system to access metadata that identifies at least one primary key defined for a table;

third computer readable program code means for enabling the computer system to use the primary keys to obtain record identification information that uniquely identifies a record being modified by a positioned update action, wherein said positioned update action updates a record at a current position of a specified cursor, and

fourth computer readable program code means for enabling the computer system to request that said database management system modify a record identified by said record identification information.

6. The computer program product of claim 5, firer comprising computer readable program code means for enabling the computer system to determine whether the information obtained by said second computer readable program code means uniquely identifies a record.