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How do you make a redo log inactive?
Ensure your redo log group is INACTIVE by querying V$LOG. If ACTIVE, switch the log (ALTER SYSTEM SWITCH LOGFILE) and wait until the status is INACTIVE. Next, drop the online redo log (with the ALTER DATABASE DROP LOGFILE GROUP x) command.
What is redo log in MySQL?
The redo log is a disk-based data structure used during crash recovery to correct data written by incomplete transactions. By default, the redo log is physically represented on disk by two files named ib_logfile0 and ib_logfile1 . MySQL writes to the redo log files in a circular fashion.
How do I view a redo log file?
The V$LOGFILE view can be used to find the datafiles for the redo logs. SVRMGR> select * from V$LOGFILE; GROUP# STATUS MEMBER —— —— —————————— 1 /t01/oradata/MYDB/redo.
Is it permissible to drop a redo log file?
It is permissible to drop redo log files so that a multiplexed redo log becomes temporarily asymmetric. For example, if you use duplexed groups of redo log files, you can drop one member of one group, even though all other groups have two members each.
How to drop a redo log group in SQL?
Drop a redo log group with the SQL statement ALTER DATABASE with the DROP LOGFILE clause. The following statement drops redo log group number 3: When a redo log group is dropped from the database, and you are not using the Oracle Managed Files feature, the operating system files are not deleted from disk.
How to delete a redo log file in Oracle?
To make this process faster, issue command which will tell the Oracle database to free the buffer by writing it from the memory to physical disks. After the above command, check for the status in the V$LOG and it will show INACTIVE for all the redo log groups except for the current one.
How does the redo log protect the database?
Redo entries record data that you can use to reconstruct all changes made to the database, including the undo segments. Therefore, the redo log also protects rollback data. When you recover the database using redo data, the database reads the change vectors in the redo records and applies the changes to the relevant blocks.