Again I. Now, I want to know any document where explain me the settings of oracle parameters respect to memory for a system SAP R/3. For instance, for the value of db_block_buffers, the shared_pool_size and the log_buffers.
I am trying setting the parameters for our oracle database to tuning our system.
80 % of RAM for SGA is too big and may not be optimal also. You can start with 2GB and slowly increase so that the HIT Ratio is around 90%. Also remember that RAM is needed for other processes, user sessions and PGA.
In Oracle ERP would be 1.5 shared pool size and .5 db_block_buffers, but that's because Oracle Apps. use a lot of PL/SQL.
If this is not your case you can set it the other way .5G shared pool and 1.5 db_block.
I have been told that log_buffer >=20M doesn't give you any performance.