Functional compensation in a heterogeneous, distributed database environment

• US 5,706,499 A
• Filed: 06/06/1995
• Issued: 01/06/1998
• Est. Priority Date: 09/29/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wang, Yun, Kleewein, James C., Lin, Eileen T.
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Homere, Jean Raymond
• Application Number:
  US08/466,924
• Time in Patent Office: 945 Days
• Field of Search: 395/610, 395/602, 395/601, 395/603, 395/200.03, 395/200.06, 395/200.09, 395/604, 395/617, 395/619, 395/200.19, 395/200.14, 395/182.1, 364/DIG. 1
• 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 and method for compensating for functional differences between heterogeneous database management systems, wherein data associated with a client is distributed among the heterogeneous database management systems, is discussed. The system simulates support of multiple pending actions on a single connection in any of the heterogeneous database management systems which does not support multiple pending actions on a single connection. Also, the system: (1) simulates support of cursors declared "with hold" in any of the heterogeneous database management systems which does not support cursors declared "with hold"; (2) simulates support of positioned update actions in any of the heterogeneous database. management systems which does not support positioned update actions; (3) simulates support of host variables in any of the heterogeneous database management systems which does not support host variables; and (4) compensates for security log-in procedure differences between the heterogeneous database management systems.

Claims

1. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for compensating for functional differences between heterogeneous database management systems, wherein data associated with a client is distributed among said heterogeneous database management systems, said method steps comprising:

(1) simulating support of multiple pending database actions on a single connection, said single connection being a logical link between a client and a database instance, wherein said database instance is instantiated in any of said heterogeneous database management systems which does not support multiple pending database actions on a single connection;

(2) simulating support of cursors declared "with hold" in any of said heterogeneous database management systems which does not support cursors declared "with hold"; and

(3) compensating for security log-in procedure difference between said heterogeneous database management systems, said step of compensating comprising the steps of;

(a) receiving a local user identification and a local password when a user logs into said client;

(b) receiving a database statement issued by said client;

(c) identifying which of a plurality of database instances instantiated from said heterogeneous database management systems are needed to process said database statement;

(d) selecting one of said identified database instances;

(e) determining whether a record associated with said user and said selected database instance exists in a log-in table;

(f) if a record associated with said user and said selected database instance exists in said log-in table, then logging into said selected database instance using information contained in said record;

(g) if a record associated with said user and said selected database instance does not exist in said log-in table then logging into said selected database instance using said local user identification and said local password; and

(h) performing steps (d)-(g) for each of said identified database instances.

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

a computer usable medium having computer readable program code means embodied in said medium for causing the computer system to compensate for functional differences between heterogeneous database management systems, wherein data associated with a client is distributed among said heterogeneous database management systems, said computer readable program code means;

computer readable first program code means for causing the computer system to effect a simulation of support of multiple pending database actions on a single connection, said single connection being a logical link between a client and a database instance, wherein said database instance is instantiated in any of said heterogeneous database management systems which does not support multiple pending database actions on a single connection;

computer readable second program code mean for causing the computer system to effect a simulation of support of cursors declared "with hold" in any of said heterogeneous database management systems which does not support cursors declared "with hold"; and

computer readable third program code means for causing the computer system to effect a compensation for security log-in procedure differences between said heterogeneous database management systems, said computer readable third program code means comprises;

computer readable program code means for causing the computer system to effect a reception of a local user identification and a local password when a user logs into said client;

computer readable program code means for causing the computer system to effect a reception of a database statement issued by said client;

computer readable program code means for causing the computer system to effect an identification of a database instance instantiated from said heterogeneous database management systems that is needed to process said database statement;

computer readable program code means for causing the computer system to effect a determination of whether a record associated with said user and said database instance exists in a log-in table;

computer readable program code means for causing the computer system to effect a logging on into said database instance using information contained in said record if a record associated with said user and said database instance exists in said log-in table; and

computer readable program code means for causing the computer system to effect a logging on into said database instance using said local user identification and said local password if a record associated with said user and said database instance does not exists in said log-in table.