Re: Max SGA size for 32-bit 9.2.0.6 on Solaris

I understand where you are coming from. The wording you use sound very familiar in Cary Milsap's seminars which I 100% agree. However, I think you made a mistake in assuming people do this because their only intention
is to "resolve a performance issue".

Increasing SGA will not resolve performance issue for sure. But it CAN resolve capacity issue. I am a big fan of very large SGA because my statistics show that it cuts down CPU utilization significantly. Sometimes this increase can avoid a CPU upgrade for me.

Free memory beyond a safety range is all wasted. Now-a-days even the smallest box comes with tons of memory by default. I think one should always maximize SGA to a safe range and nobody should still be using 32-bit and limit your SGA to a few GB while having another several, or even ten's of GB idling. Basically it is use it or waste it. I see nothing wrong trading idle memory with a few cycles of CPU.

sybrandb_at_yahoo.com wrote:
> The maximum SGA size is obviously limited by the maximum address space
> in a 32-bit environment, so 2^32 -1 --> 2G.
> It very much sounds like you want to resolve performance problems by
> throwing memory at the problem. Rest assured: That methodology won't
> work, EVER.
>
> If it 'resolves' anything in your eyes, you are probably already either
> a victim of Compulsive Tuning Disorder, or adhere to the Redneck school
> of tuning, which mainly tunes by ratios.
>
> --
> Sybrand Bakker
> Senior Oracle DBA
Received on Wed Jul 06 2005 - 12:55:57 CDT