Modify the redo log size

Requirement: increased from 50 M in each group to 100 M

1. Check the script with log group information:
SELECT v $ logfile. member, v $ logfile. group #, v $ log. status, v $ log. ARCHIVED, v $ log. bytes/1024/1024, v $ log. thread #
FROM v $ log, v $ logfile
WHERE v $ log. group # = v $ logfile. group #
Order by v $ log. thread #, v $ logfile. group #;

2. Each instance has four groups of log files, so we can delete the two groups first, and then delete the other two groups after modification. The specific operations are as follows:

A. Execute a full checkpoint first.
Alter system checkpoint;

B. Delete the two groups of logs whose status is INACTIVE and archived on each node.
Alter database drop logfile group 3;
Alter database drop logfile group 4;

Alter database drop logfile group 7;
Alter database drop logfile group 8;

C. Add two groups of logs to each node. The size is 100 MB, and files are automatically generated by ASM.
Alter database add logfile thread 1 GROUP 1 ('+ DATADG', '+ DATADG') SIZE 100 M;
Alter database add logfile thread 1 GROUP 2 ('+ DATADG', '+ DATADG') SIZE 100 M;
Alter database add logfile thread 1 GROUP 3 ('+ DATADG', '+ DATADG') SIZE 100 M;
Alter database add logfile thread 1 GROUP 4 ('+ DATADG', '+ DATADG') SIZE 100 M;

Alter database add logfile thread 2 GROUP 5 ('+ DATADG', '+ DATADG') SIZE 100 M;
Alter database add logfile thread 2 GROUP 6 ('+ datadg',' + datadg') SIZE 100 M;
Alter database add logfile thread 2 GROUP 7 ('+ DATADG', '+ DATADG') SIZE 100 M;

Alter database add logfile thread 2 GROUP 8 ('+ DATADG', '+ DATADG') SIZE 100 M;

D. Delete the other two groups and then add the log group, which is the same as step B and Step c.

3. If the original log group is relatively small, you should first Add a new log group and then delete the old one to ensure that the log group is more than two.