Where is Oracle redo log file location?
Redo log files are used to record data changes to the database. The redo log files are initially specified within the CREATE DATABASE command. CREATE DATABASE . . . LOGFILE ‘/t02/oradata/MYDB/redo1.
What are redo log files in Oracle?
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 check redo logs?
Monitoring redo usage: It’s easy to use the v$log_history and the v$log view to monitor redo log history, and I have these redo log monitoring scripts. When testing for redo log usage, start the job by performing a redo log switch (alter system switch logfile), so you start with a fresh redo log.
How do I change the redo log size in Oracle 11g?
select group#, status from v$log; You may have to run the alter command up to three times to get group 1 to be CURRENT. Repeat steps 1 to 7 for group 2, group 3, and group 4. Confirm the size change to each group is now 165 Mb.
How do I drop a redo log in Oracle 11g?
To drop specific inactive redo log members, use the ALTER DATABASE statement with the DROP LOGFILE MEMBER clause. The following statement drops the redo log /oracle/dbs/log3c. rdo : ALTER DATABASE DROP LOGFILE MEMBER ‘/oracle/dbs/log3c.
How do I rename a redo log in Oracle 11g ASM?
To move or rename a logfile do the following.
- Shutdown the database.
- Rename the physical file on the OS.
- Start the database in mount mode.
- Issue the ALTER DATABASE RENAME FILE command to rename the file within the Oracle dictionary.
- Open the database.
How do I create a redo log in Oracle?
To create a new group of redo log files, use the SQL statement ALTER DATABASE with the ADD LOGFILE clause. The following statement adds a new group of redo logs to the database: ALTER DATABASE ADD LOGFILE (‘/oracle/dbs/log1c. rdo’, ‘/oracle/dbs/log2c.
What does redo log file do?
Redo log files are operating system files used by Oracle to maintain logs of all transactions performed against the database. The primary purpose of these log files is to allow Oracle to recover changes made to the database in the case of a failure.
Can we delete redo log files?
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 do I edit a redo log in Oracle?
To create a new group of redo log files, use the SQL statement ALTER DATABASE with the ADD LOGFILE clause. The following statement adds a new group of redo logs to the database: ALTER DATABASE ADD LOGFILE (‘/oracle/dbs/log1c.
How is Oracle database writes to the redo log?
How Oracle Database Writes to the Redo Log. The redo log of a database consists of two or more redo log files. The database requires a minimum of two files to guarantee that one is always available for writing while the other is being archived (if the database is in ARCHIVELOG mode).
How to move Oracle redo logfiles to new location?
1. Shutdown the database 2. Move the logfile from Old location to new location using operating system command $mv /u01/oracle/ica/log1.ora /u02/oracle/ica/log1.ora 3. Start and mount the database 4. Now give the following command to change the location in controlfile
How to clear Oracle redo log Group 3?
The following statement clears the log files in redo log group number 3: ALTER DATABASE CLEAR LOGFILE GROUP 3; This statement overcomes two situations where dropping redo logs is not possible: If the corrupt redo log file has not been archived, use the UNARCHIVED keyword in the statement.
How to change the name of a redo log file?
Rename the redo log members. Use the ALTER DATABASE statement with the RENAME FILE clause to rename the database redo log files. Open the database for normal operation. The redo log alterations take effect when the database is opened.