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Method of Terminating the IBM OS/2 Extended Edition Database Manager to Prevent User Data Integrity Problems

IP.com Disclosure Number: IPCOM000034922D
Original Publication Date: 1989-May-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Jordan, LE: AUTHOR [+3]

Abstract

Disclosed is a method that enables the IBM OS/2 Blended Extended (EE) Database Manager to shut down all operations on a database when it determines that system control structures in memory have been corrupted. When the corruption occurs, if the Database Manager detects it but allows the applications to continue, the user's permanent data could also be corrupted. OS/2 is a multi-tasking operating systems that allows multiple applications to run concurrently. The database manager also allows multiple applications to concurrently access a database. In order to serialize access to the database, the Database Manager utilizes control structures in memory that is shared by the different tasks. Each OS/2 task may have multiple sub-tasks.

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Method of Terminating the IBM OS/2 Extended Edition Database Manager to Prevent User Data Integrity Problems

Disclosed is a method that enables the IBM OS/2 Blended Extended (EE) Database Manager to shut down all operations on a database when it determines that system control structures in memory have been corrupted. When the corruption occurs, if the Database Manager detects it but allows the applications to continue, the user's permanent data could also be corrupted. OS/2 is a multi-tasking operating systems that allows multiple applications to run concurrently. The database manager also allows multiple applications to concurrently access a database. In order to serialize access to the database, the Database Manager utilizes control structures in memory that is shared by the different tasks. Each OS/2 task may have multiple sub-tasks. The Database Manager could be running in one sub-task and the application in another where the application could possibly do something that causes the entire task to be abnormally terminated by the operating system. If the Database Manager is working with the control structures within its sub-task, the control structures could be left in an unknown state.

If the Database manager in other tasks used this structure, it is very likely that the data in the database on the media would be left in an unknown state. To prevent the corruption of user's data, the Database Manager utilizes an OS/2 task termination exit to detect an abnormal termination of the application. At that time the Database Manager determines whether the application terminated while requesting work on the database through the Database Manager, or whether the application terminated while performing application specific functions. If the application ends abnormally while no work is being performed for the application by the Database Manager, then there is no danger of corrupting the control structures. The Database Manager simply performs its standard clean up for an application failure. If the Database Manager detects that it was perform...