renicing processes and Oracle

[Inesa Clinko]

Hi! :)
I have heard,that renicing in HP-UX of
several main processes in Oracle,
like DBWR,LGWR,ARCH and so on...
could improve DB-performnce?
Does anybody know more about it?
Any experiance? Please explain me which processes could be reniced, and which not?
What can be the values?
Excuse me, if it is stupid question.. :))

[Graham Cameron_1]

Inesa

Where did you hear that?
It's a new one on me, and I can't find anything on metalink, but I'm willing to be convinced.

-- Graham

[Stan_17]

yes or no! however, renicing oracle bg processes is totally unsupported. so i wouldn't muck around them.

-
hth,
Stan

[Steven E. Protter]

Oracle is designed to work with standard process assignment. It is best not to mess with it.

You can use paid add in products like PRM to tune performance and give oracle higher priority.

But: What happens if you give Oracle too much priority and there aren't enough cycles for I/O?

Answer: Not very much.

SEP

[Hein van den Heuvel]

'It depends'.

If you consider to start turning knobs, be sure to have a measurement in place for feedback. At least 'overall trhoughput', like the run time for a typical batch job.

You may also have a few specific, heavy hitting, statspack timed events in mind (for example log file sync) when you turn a know like the lgwr prio.

As a first stab to playing with priority I'd recommend to add the init.ora param:
HPUX_SCHED_NOAGE = 178

Hein.

[Thierry Poels_1]

hi,

priorities of Oracle processes, either system or client processes, should not be changed on OS level. This will do more harm than good. Let Oracle take care of itself.

regards,
Thierry.