Adjust the redo log file size in oracle rac, racredo

Adjust the redo log file size in oracle rac, racredo
Adjust the size of the redo log file under rac


(1) view the current log information:


Select * from v $ logfile;


(The path in step 2 can be seen in the MEMBER column here. The redo file name is named by yourself, for example, redo07.log)

(Note: The log group is now in 6 groups)



(2) Add log files for each node: (add three groups of logs for each node)
1. Node 1
Alter database add logfile thread 1 group 7' + data/... (Path in single quotes) 'size 2048 m;
Alter database add logfile thread 1 group 8' + data/... (Path in single quotation marks) 'size 2048;
Alter database add logfile thread 1 group 9' + data/... (Path in single quotation marks) 'size 2048;


2. Node 2
Alter database add logfile thread 2 group 10' + data/... (Path in single quotes) 'size 2048 m;
Alter database add logfile thread 2 group 11' + data/... (Path in single quotes) 'size 2048 m;
Alter database add logfile thread 2 group 12' + data/... (Path in single quotes) 'size 2048 m;

(3) manually switch logs and delete the previous logs: (this step is executed repeatedly until all group, are deleted)

View the log file STATUS column (STATUS ):

SELECT * from v $ LOG;


Only the STATUS column is inactive can be deleted:
Alter database drop logfile group 1;
Alter database drop logfile group 2;
Alter database drop logfile group 3;
Alter database drop logfile group 4;
Alter database drop logfile group 5;
Alter database drop logfile group 6;

Alter system switch logfile; (switching logs can change the status of the status column before deleting)

If the status cannot be changed, use this: alter system archive log current;

 

Last: Delete the previous redo log file (delete at the operating system level)

Writing redo log file in oracle architecture Course

Oracle has three log groups by default. Each group has one log member.
The two or more members in each group are the same in each log group. The reason why there are multiple log members is used for redundancy, prevent system unavailability due to a fault in the member of the log team. Oracle writes data to each member in the log group in parallel.

The LGWR process cyclically writes data to each log group. When a log group is full, it automatically switches to the next log group for writing. After all the logs are fully written, the system will return cyclically and find the first log group to continue writing. At this time, the previous log information will be overwritten.

If you enable the archive mode, when a log group is full, the archiving process archives the full log file and generates an archive log, it is equivalent to a copy of the original online log.

Oracle Log File Size

Redo size: the total number of times redo occurs (and therefore logs are written to the buffer), in bytes. It's not the number of transactions you mentioned .. In addition, REDO is generated not only by UPDATE .. Your DELETE and INSERT operations will also generate REDO
You need to look at the execution plans of your UPDATE statements .. To see how to optimize it ..