What is meant by redo logs?

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.

How do I view a redo log file?

The V$LOGFILE view can be used to find the datafiles for the redo logs. SVRMGR> select * from V$LOGFILE; GROUP# STATUS MEMBER —— —— —————————— 1 /t01/oradata/MYDB/redo.

How do I clear a current redo log?

In case you want to clear out your Redo Log files in a situation of an unexpected failure or corruption, you can use the alter table clear logfile command as follows: Sql>alter database clear logfile group 3; Clearing an Unarchived Redo Log File.

What does a redo log on a database do?

The Redo Logs consist of two or more pre-configured files that log all the changes made to the database. This helps the database instance in the recovery of data in case of a failure.

What does Archive Log mode on redo log mean?

What is archive log mode? Archive log mode simply means that a redo log file is copied (archived) to another location before being reused. This yields a complete history of all changes made to the database. How do I view the redo logging status of my database?

How to check the size of a redo log?

V$LOGFILE is used to check the file name and location of redo logs. V$LOG and V$LOGFILE view can be combined to get the detailed information like redo log size, redo log members, thread, groups, sequence, status etc.

How to create redo log files and backups?

The redo log files are initially specified within the CREATE DATABASE command. CREATE DATABASE . . . LOGFILE ‘/t02/oradata/MYDB/redo1.rdo’ size 4m, ‘/t03/oradata/MYDB/redo2.rdo’ size 4m; Or if redo log files are mirrored, you can have groups of redo log files. CREATE DATABASE . . .