0
The most crucial structure for recovery operations is the redo log, which consists of two or more preallocated files that store all changes made to the database as they occur. Every instance of an Oracle Database has an associated redo log to protect the database in case of an instance failure.
Wiki User
∙ 12y ago
Wiki User
∙ 11y agoit contains two or more changes of a database in a previous state which could be use for recovery.
Add your answer:
Earn +20 pts
How many maximum Redo Logfiles one can have in a Database?
In a database we can create 255 maximum redo log files Depends on what you specified for MAXLOGFILES during database creation (manually) or what you specified for "Maximum no. of redo log files" with DBCA. sri
What are the different types of physical files in the Oracle 9i?
* Database datafiles - contain the data itself * Control files - binary files containing information about the database (name, files, backup...) * Online redo logs - files, which record every transaction in the database * Parameter files - database parameter file * Other database related files - password files, alert log, trace files...
How do you store log files into event viewer?
application log, security log, system log
What is Aries recovery algorithm.?
three main principles lie behind ARIES: - Write ahead logging: Any change to an object is first recorded in the log, and the log must be written to stable storage before changes to the object are written to disk. - Repeating history during Redo: On restart after a crash, ARIES retraces the actions of a database before the crash and brings the system back to the exact state that it was in before the crash. Then it undo the transactions still active at crash time. - Logging changes during Undo: Changes made to the database while undoing transactions are logged to ensure such an action isn't repeated in the event of repeated restarts. The ARIES recovery procedure consists of three main steps : - Analysis : It identifies the dirty (updated) pages in the buffer and the set of transactions active at the time of crash. The appropriate point in the log where REDO operation should start is also determined. - REDO phase : It actually reapplies updates from the log to the database. Generally the REDO operation is applied to only committed transactions. However, in ARIES, this is not the case. Certain information in the ARIES log will provide the start point for REDO, from which REDO operations are applied until the end of the log is reached. Thus only the necessary REDO operations are applied during recovery. - UNDO phase : The log is scanned backwards and the operations of transactions that were active at the time of the crash are undone in reverse order. The information needed for ARIES to accomplish its recovery procedure includes the log, the transaction table, and the dirty page table. In addition, checkpointing is used.
What if you can't enter the second floor of the necromancy tower in aqworlds?
Then you should log out, clear your cache, log back in and redo the speed reading quest.
What directory holds the bulk of system log files in Linux?
/var/log
How do you see system log files in Linux?
vim /var/log/messages Check for other files in the log directory, starting with message, followed by a number, to find the information you need.
How do you find the log files in mac el capitain?
Which log files? This may help you. http://pondini.org/OSX/Logs.html
What type of server generates log file?
Traffic Server generates log files.
What is Ine in log?
A log in password is a secret word or phrase to secure your files on the computer.
What is a log in password?
A log in password is a secret word or phrase to secure your files on the computer.
Locate the important log files on your Linux systems?
they're probably somewhere in /var/log
