Re: Sun E4500, 4GB Mem, 2 processors, Oracle running like a dog?

Chris M wrote:
>
> Hi,
>
> I'm the DBA for a website and periodically, under heavy load, the server
> falls on it's knees. using the top utility, it hits 7,8 and 9. If I flush
> the shared_pool then the load goes down again...so I believe the shared_pool
> is fragmented. BUT the load still seems quite high, around 1-2 for most of
> the day.
>
> I think we need more processors, to manage 4GB of memory, and I've heard the
> standard of 1 processor per 512M of memory. I'm being told by my boss that I
> can never have enough memory, but I'm sure that's not the case. There's no
> swapping going on and the hit rates are high (99) in the database. The
> processor does hit 0 idle time though during heavy load.
>
> Has anyone got any experience of this situation? We're going to try and put
> 2 more processors in the machine as a test. The only database activity is
> 'select' and a small minority of inserts (maybe 100 an hour).
>
> Utlbstat/estat only really shows the 'latch free' statistic as a problem
> when the server is on it's knees...actually library latch contention. We can
> get around this by changing our code to use bind variables, but I still
> think we need more processors?
>
> Thanks
> Chris

Its quite possible your shared pool is actually too large - a common problem when people have RAM to burn...

Check v$sgastat for free memory...

More importantly, if you are not using bind variables you may as well kiss your performance goodbye...

HTH

-- 
===========================================
Connor McDonald
http://www.oracledba.co.uk

We are born naked, wet and hungry...then things get worse