Lost write detection and repair
US7627614B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 2005 |
| Grant date | Dec 1, 2009 |
| Priority date | — |
| Expiry date | Jan 29, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99954
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques are provided for detecting lost writes so that data corruption can be avoided. According to one technique, lost writes are detected by comparing version numbers that are indicated in redo log entries with version numbers that are indicated in corresponding blocks in a standby database. According to one technique, which may be used in conjunction with the above technique, lost writes are detected by logging read operations that occur relative to a primary database, and comparing version numbers that are indicated in read log entries with version numbers that are indicated in corresponding blocks in a standby database. According to one technique, lost writes are detected by comparing, in response to read operations, (a) version numbers that are stored in a persistent in-memory cache with (b) version numbers that are indicated in corresponding blocks that are read from a primary database.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.