Fault-tolerant timestamp generation for multi-node parallel databases
US6125368A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1997 |
| Grant date | Sep 26, 2000 |
| Priority date | — |
| Expiry date | Feb 28, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99953
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Every node in a multi-node parallel database system maintains a logical clock for generating timestamps. The logical clocks are synchronized by attaching a current timestamp to every message that is sent by a node. When a node receives an incoming timestamp that is greater than the value indicated by the associated logical clock, it sets the associated logical clock forward to at least the value of the timestamp. Each node continually sends and receives a message including a timestamp at least once in a prescribed period of time. Moreover, each node maintains a high watermark that represents a time greater or equal to the highest time of any logical clock in the multi-node parallel database system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.