Default redo log 100mb???????

Question

hi all
my database is runing in archive mode
(database oracle 9i rel 2)
when i issue
SQL> SELECT * FROM V$LOG;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
1 1 59 104857600 1 NO CURRENT 3519698 20-FEB-04
2 1 57 104857600 1 YES INACTIVE 3477638 20-FEB-04
3 1 58 104857600 1 YES INACTIVE 3479786 20-FEB-04
its funny default size of redo log [b]is 100MB
every archive log file is created on my database of size 100mb.
1.whats the reason of deafult size of 100mb
2.its my production database and i want to change its size to 1mb
plz give some suggestion to change it.because my boss don''t want any mistake.
if solution is drop and recreate then it give me trouble all time when i do this. so plz give suggestion for change its size
thanks
kuljeet pal singh

Answer 1

The sizes for the Redo Logs members are determined by several issues:
1.- The switching time that you want.
2.- The switching time is determined according what is the amount of time ( This represent data ) that you are disposed to lose in case of you lose all redo members of one Redo Log group.
3.- The switching time is determined according as well to the sizes for Archive Redo Logs to store and handle them in a confortable way.
4.- In some occasions if you have redo members with low size like 1m , that can affect the performance of your database.
5.- when they are too long the database has to wait while they archives redo logs are generated.
If you want to change the size of redo members you have to create new redo log groups and after go removing the groups that you do not want. When you are doing this you have to have at least 2 Redo Log Groups.
Joel Pérez
http://otn.oracle.com/experts