Can someone help me with SGA tuning. What is the standard for SGA values.
I am running 8i (8.1.5) on Solaris 2.6, total allocation to SGA is 100MB of 2GB (total memory on the system). Out of this total:
54 MB buffer cache with hit ratio of 96.8 %
45 MB shared pool with hit ratio of 74.5 %
171 KB redo buffer

Drilling down furhter:
data buffer cache: 15% on average and 60% max.

In regards to the above information, is the data buffer cache considered to be part of the buffer cache? If they are one in the same, what is an acceptable value for it? What is the standard for shared pool hit ratio?

on another note, we are only using 100 MB of SGA which left us almost 1.8GB of memory. However, when I ran top, only 45 MB of memory is free. when I sorted by RS memory, oracle processes comes right on top. What should I do next? Looking into turning off certain function in oracle which we are not using such as JAVA? How do I find out what is causing the memory consumption? I am tempted just to run the system without starting oracle, just to check out how much is the system using memory. This way I know for sure, that's it's oracle if the system is not consuming memory.

The fool i used to get the above information is Tora. I am not sure of it's accuracy. But people who uses it, gives it good praises.

Thanks in advance for your help.