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I have a question regards to some Tuning.
Basically we have sun 450 server with 2 processes.
We want to do some appln/system tuning
how do i increase db_writer_processes from 1 to 2(what is the max)
how do i increase the log_writer processes (aswell) what is the parameter.. i could not find in show parameters log.
similarly what are all the views involved for this kind of query or situation.
thanks
You can change the number of db writers by changing the db_writer_processes parameter. Keep in mind, you must also change the db_block_lru_latches at the same time.
how do you change the same. Alter session, system ?? How ??
secondly, how about log_writer_process ??
as well could you also give me what are the views available for the same??
Thanks for the reply Marist89
also should we bounce the database.. after we do this..
The range for the db_writer_processes = 1-10
You have to set the number of processes that you want to be started, in the init<SID>.ora file that could be found under the $ORACLE_BASE/admin/<sid>/pfile
I'm not aware of whether there is a way to increase the log_writer processes. I beleive that it was an dynamic parameter whose number gets decided by oracle. If your system is in the archive mode then, you could set a max limit on the archiver processes.
V$sgastat
V$bgprocess
v$process
v$thread
and there are others which are inter-dependent on others.
Sam
Yes you have to bounce after the changes.
Sam
you need to add these changes in your init.ora file, if you change them dynamically (alter session/system) and then bounce the DB you will not have your changes there. Once you change your init.ora parameter file, then bounce the DB and yer all set.
- Magnus
Thanks for all the replies guys. But looks like everyone ignored the command for the changes..
what command do you need.
To perform the changes go to the initSID.ora file add the
db_writer_process = 2
save that file
come to the prompt,
$> svrmgrl
SVRMGRL> connect internal <----- make sure that
your ORACLE_SID=
is set in your enviromnet
SVRMGRL> shutdown immediate
SVRMGRL> startup
_______________________________________________
This should put the changes in place.
Sam
There is no command to make these changes on-the-fly.
You must change your init.ora parameter and then bounce the database (shutdown/startup) in order for the changes to take effect.
Cool.. Thanks onceagain..
I am very clear now.
Since the answers were betn dynamic and static changes I was hoping to use alter system/session commands..
If it is init.ora it has to be bounced.
How do we check the performance after changes??
Any ideas? (Should we run a big job etc.,)..
If you thought you needed to change this parameter in the first place, you probably had some reason for choosing this parameter? No? Re-run the scenario that lead you to changing this parameter.
We assumed you knew how to add parameters in your init.ora file and then shutdown/startup the DB. Just follow the instructions above and you should be all set.
You also need to know the location of the init.ora file :-P
- Magnus
To view the performance do
alter system set timed_statistics = true.
then you could run the statspack utility, which could be found if you have 8i under
$ORACLE_HOME/rdbms/admin/statspac.doc
also you could run the utlbstat.sql to build the stats tables and then utlestat.sql to create a report. These above mentioned scripts would build only dynamic temp tables, on the other hand if you want to use the statspack, that would build some static tables which you could use for the future analysis too.
All the above said scripts were found under the above stated path on unix.
Sam
Thx a lot Sambavan. I shall start looking into Statspack.
You guys are really great. Great knowledge.dmp here..
Check: if you have non zero value for DBWR_IO_SLAVES, Oracle will always use only one DBWn process, even youhave specified more than one DBW.
There is no parameter called log_writer_process in Oracle.
It's just my curiosity, why do you want to increase this value.
Regards,
abhijit
so you guys are saying that in order to increase IO we can use db_writer_processes = 2. In order to use db_writer_processes parameter you will have to invoke disk_asynch_io=true?
thanks
Jigar