EP0402542A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of removing uncommitted changes to stored data by a database management system
Assignee: International Business Machines Corp
•
Filing: 1989-06-13
•
Granted: —
•
Expires: 2009-06-13
Abstract
Abstract A method of removing uncommitted changes made to stored data by a database management system, wherein the system stores a duplicate copy of data prior to effecting changes to the original copy, and upon failure of the system, or a transaction or transactions effecting the changes replaces the copy containing uncommited changes by the duplicate copy, characterised in that, in the case of failure of the system to replace the original copy (ie in the case of a backout failure), the system prevents subsequent attempts by the system to further change the data until the uncommitted changes have been removed by a process of backout failure processing, and wherein a batch backout utility program uses a set of system log records to bracket the duration of the backout failure for a particular file to track: whether the system completed its backout failure processing; which transactions had failed backout; and which transaction was the first to have a backout failure.
Inventors
- 👤 Samuel David Borman
- 👤 Arthur Jonathan Tyrrell
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 03:46
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/14; G06F11/1471; G06F11/22; G06F11/2205; G06F2201/00; G06F2201/87; G11; G11C; G11C29/00; G11C29/70; G11C29/74; Y; Y10; Y10S; Y10S707/00; Y10S707/99951; Y10S707/99952; Y10S707/99953
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
159 words
A method of removing uncommitted changes made to stored data by a database management system, wherein the system stores a duplicate copy of data prior to effecting changes to the original copy, and upon failure of the system, or a transaction or transactions effecting the changes replaces the copy containing uncommited changes by the duplicate copy, characterised in that, in the case of failure of the system to replace the original copy (ie in the case of a backout failure), the system prevents subsequent attempts by the system to further change the data until the uncommitted changes have been removed by a process of backout failure processing, and wherein a batch backout utility program uses a set of system log records to bracket the duration of the backout failure for a particular file to track: whether the system completed its backout failure processing; which transactions had failed backout; and which transaction was the first to have a backout failure.
Claim 2
Independent Claim
159 words
A method of removing uncommitted changes made to stored data by a database management system, wherein the system stores a duplicate copy of data prior to effecting changes to the original copy, and upon failure of the system, or a transaction or transactions effecting the changes replaces the copy containing uncommited changes by the duplicate copy, characterised in that, in the case of failure of the system to replace the original copy (ie in the case of a backout failure), the system prevents subsequent attempts by the system to further change the data until the uncommitted changes have been removed by a process of backout failure processing, and wherein a batch backout utility program uses a set of system log records to bracket the duration of the backout failure for a particular file to track: whether the system completed its backout failure processing; which transactions had failed backout; and which transaction was the first to have a backout failure.
Claim 3
Dependent Claim
17 words
A method as claimed in claim 1 wherein the database management system is a transaction processing system.
Claim 4
Dependent Claim
54 words
A method as claimed in claim 1 wherein the system contains a backout failure log record, comprising the information that the batch backout utility will need, to calculate if it is safe to attempt backout, where to start, where to stop and which original records it must re-apply in order to backout uncommitted changes.
Claim 5
Dependent Claim
39 words
A method as claimed in claim 3 wherein fields in the backout failure log record include a FIRST flag set if it is the first backout failure log record for a given data set; dataset name; and transaction identifier.
Claim 6
Dependent Claim
75 words
A method as claimed in claim 3 or claim 4 wherein there are three different types of backout failure log record: (i) backout failure log record FIRST, indicating which task was the first to have a backout failure for a given dataset; (ii) backout failure log record SUBSEQUENT, indicating which tasks had backout failures subsequently for a given dataset; (iii) backout failure log record END, indicating that backout failure has completed for a given dataset.
Claim 7
Dependent Claim
19 words
A method as claimed in claim 5 wherein the backout failure logic is represented by pseudo code as follows:
Claim 8
Independent Claim
28 words
A method of removing uncommitted changes made to stored data by a database management system, substantially as hereinbefore described with reference to the pseudo code of Example 2.
Claim 9
Independent Claim
28 words
A method of removing uncommitted changes made to stored data by a database management system, substantially as hereinbefore described with reference to the pseudo code of Example 2.
Claim 10
Dependent Claim
13 words
A database management system using a method as claimed in any preceding claim.
References Cited (Backward Citations)
EP0098928A2
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.