What is a log sequence number?
Are you preparing for IT certification? With practice questions, study notes, interactive quizzes, tips and technical articles, uCertify PrepKits ensure that you get a solid grasp of core technical concepts to ace your certification exam in first attempt.
What is a log sequence number?
Rating:
A log sequence number uniquely identifies a set of redo records in a redo log file. When the log writer process (LGWR) stops writing to one online redo log file and switches to another, Oracle automatically assigns the new file a log sequence number. For example, if a database contains two online redo log files, Oracle assigns log sequence number 1 to the first file when the LGWR starts writing to it. When the first online redo log file becomes full, and the LGWR switches to the second online redo log file, Oracle assigns log sequence number 2 to the second file. When the LGWR switches back to the first file, Oracle assigns it log sequence number 3, and so forth.
Rating:
Was this information helpful?
Other articles
- How are archive destinations specified?
- What is a cancel-based recovery?
- What is an open backup?
- What is Recovery Manager (RMAN)?
- What is instance recovery?