Control file parallel write

Question

Hi,
From my statspack report one of the top wait events is control file parallel write.
               Wait Time
Event          Time     Percentage Avg. wait
Control file      11000     3.61% 11.68
parallel write
How can I tune the control file parallel write event?
Right now for this instance I have control file multiplexed onto
3 different drives L. M. N
Thanks

Answer 1

If you are doing excessive log swaps, you could be generating too many checkpoints. See how many log swaps you have done in v$loghist. It is also possible to reduce the number of writes to log files by adding the /*+ APPEND */ hint and the "nologging" to insert statements to reduce the amount of log files filled.
I have also combined update and delete statements to generate fewer writes to the log files.
You can recreate the log files larger with :
alter database drop logfile group 3;
ALTER DATABASE ADD LOGFILE THREAD 1 GROUP 3 '/oracle/oradata/CURACAO9/redo03.log' size 500m reuse;
ALTER DATABASE ADD LOGFILE member '/oracle/oradata/CURACAO9/redo03b.log' reuse to GROUP 3;
alter system switch logfile;
alter system checkpoint;
alter database drop logfile group 2; -- and do group 2 etc.