EP0236743A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for restarting a long-running, fault-tolerant operation in a transaction-oriented data base system
Assignee: International Business Machines Corp
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Filing: 1987-02-05
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Granted: —
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Expires: 2007-02-05
Abstract
Abstract A restartable load without logging method permits the restart of a LOAD operation from the last COMMIT point without requiring the writing of images of loaded records to the log. Instead, the method logs only a minimal amount of information, recording positions within the data sets to be loaded and within the tablespace being loaded.
Inventors
- 👤 Roger Alan Reinsch
- 👤 Melvin Richard Zimowski
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 11:29
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/14; G06F11/1474; G06F11/1402; G06F11/1405; G06F11/141; G06F2201/00; G06F2201/80
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
164 words
A method for executing a restartable LOAD operation in a transaction-oriented data base system, all changes to the data base being written to a log in support of recovery in the event of interruption, each transaction utilizing BEGIN, COMMIT, or ROLLBACK primitives to bound said transaction, REDOs ensuring transaction return to the most recent COMMIT point, while UNDOs ensuring return to the transaction BEGIN point, comprising the steps of: (a) reiteratively moving a predetermined quantity of a sequential data set and appending said quantity to the end of a data base system formatted object, recording the current position within the data set and establishing another end position within the formatted object, said step continuing either until the data set becomes exhausted or a transaction in progress becomes interrupted; and (b) in the event of transaction interruption, restarting the operation from the last COMMIT point by emulating REDO and UNDO without recourse to the before and after images of the formatted object from the log.
Claim 2
Independent Claim
164 words
A method for executing a restartable LOAD operation in a transaction-oriented data base system, all changes to the data base being written to a log in support of recovery in the event of interruption, each transaction utilizing BEGIN, COMMIT, or ROLLBACK primitives to bound said transaction, REDOs ensuring transaction return to the most recent COMMIT point, while UNDOs ensuring return to the transaction BEGIN point, comprising the steps of: (a) reiteratively moving a predetermined quantity of a sequential data set and appending said quantity to the end of a data base system formatted object, recording the current position within the data set and establishing another end position within the formatted object, said step continuing either until the data set becomes exhausted or a transaction in progress becomes interrupted; and (b) in the event of transaction interruption, restarting the operation from the last COMMIT point by emulating REDO and UNDO without recourse to the before and after images of the formatted object from the log.
Claim 3
Dependent Claim
30 words
A method according to claim 1, wherein said system includes a first address space containing sequential data sets and a second address space containing the data base system formatted object.
Claim 4
Dependent Claim
15 words
A method according to claim 2, wherein the data base object is a relational tablespace.
Claim 5
Dependent Claim
41 words
A method according to claim 1, wherein the LOAD operation moves data sets from the first into the second address space by a series of nonoverlapping suboperations, said LOAD operation not employing before or after images of any data being moved.
Claim 6
Dependent Claim
43 words
A method according to claim 1, wherein step (b) is further limited in that in the event of restart interruptions occurring while performing the restart step, generating an idempotent outcome by restarting the operation again as if the restart interruption had not occurred.
Claim 7
Dependent Claim
44 words
A method according to claim 1, wherein step (b) is further limited in that emulating REDO and UNDO includes restoring the processing state of the operation to the state existing just prior to the last COMMIT utilizing log positional information and log independent processing.
Claim 8
Dependent Claim
26 words
A method according to claim 1, wherein the restart of the operation selectively occurs at a COMMIT point prior in time to the last COMMIT point.
Claim 9
Dependent Claim
25 words
A method according to claim 7, wherein the initialization COMMIT point of the operation is used as a bound to effectuate ROLLBACK of the operation.
References Cited (Backward Citations)
No citation records indexed.
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