number of dbwr processes under ibm aix

[beksalur]

hi,
our platform is Oracle 9i under ibm aix 5.2 .there is 2 cpu
at db server.
should we use multiple DBWR processes or dbwr_slaves under a dbwr process? which sql should i run to determine it?

Thanks in advance.

 

[JtheRipper]

Hi,

Since you have only 2 cpu's (depends on how busy your DB will be obviously) I would go for dbwr_slaves as it is beneficial in write intensive envoronments and it simulates asynchronous IO. You can look at "free buffer waits" in the v$system_event view to see if the value is increasing of if it is a high value.

 

[beksalur]

hi,
but our OS(aix 5.2) is now working at asynchronous IO. why i would want to simulate async I/O to set the dbwr_slaves parameter while our os is already working at async i/o mode.

what do you think?