memory database parameters for SAP

[rtorres]

Hello!

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.

Thanks for your help.

[tamilselvan]

Configuring SGA depends upon available Physical Memory.
How much does the machine have?

[rtorres]

We have 8 GB on the central database instance and we have 3 applications servers. The SAP documentation say me that I must to use the 0.8*RAM for the SGA and the rest for SAP work processes

[tamilselvan]

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.

[rtorres]

How can I distribute the 2 GB for all of the SGA?

[rcaballe]

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.

[rtorres]

Now, our system is setting as follow:

db_block_buffers 1073741824 bytes
log_buffers 1056768 bytes
shared_pool_size 698351616 bytes
shared_pool_reserved_size 69206016 bytes



We don´t use a lot of storage procedures PL/SQL because this is a SAP R/3 system and the procedures that use are programmed on ABAP language.

I don´t kwon if this is the correct distribution for our SAP R/3 system.

[rcaballe]

There aren't "correct" parameters, so far I see them right.
You will have to monitor the first days a little harder and don't count the "load days".

[rtorres]

Thanks for your help.

I will be monitoring the system to catch this information.