Identifying appropriate undo during a forward pass through a log
US7036044B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 2002 |
| Grant date | Apr 25, 2006 |
| Priority date | — |
| Expiry date | Aug 6, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1471
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The location of appropriate undo data necessary for reversing an effect of an operation performed at a computer system is identified during a forward pass through a log. A cycle count can be used to determine if appropriate undo data is stored in an object or is stored in auxiliary storage. If appropriate undo data is stored in an object and the undo data would be potentially lost by processing a redo log entry to modify the contents of the object, the appropriate undo data is copied to auxiliary storage. In some embodiments, a secondary computer system receives log entries from a primary computer system. The secondary computer system can identify undo data necessary to reverse an effect of an operation performed at the secondary computer system from received log entries. Identified undo data can be copied auxiliary storage at the secondary computer system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.