Buffer Qua is 60 % , incre the sga_max_size and db_cache_size on wht basis

[Former Member]

Dear All,

In our XI Production system, data buffer quality is 60%, as i found out that sga_max_size(1.1 GB) and db_cache_size(570 MB) not set as per the standard, and also they are less when compared with development(8 GB RAM).

Our RAM size in PRD is 10 GB,and when i see in topas 90% of RAM is filled, if we increase these parameter by 1GB, i think System's overall perform will be effected as the total RAM will be filled. Please suggest me how to solve the problem and on what basis these parameters should be set(what percent of RAM).

OS : AIX 5.3

SAP XI 7.00

DB : Oracle

Please inform whether i have to include any other info

Regards,

Balaji Vedagiri

[Former Member]

Hi Balaji,

The value of DB_CACHE_SIZE Size depends on the available RAM i..e in this Case 10 GB. (Please go through Notes 789011, 617416, 618868, 619188) . Can you inform why weren't the parameter set to the standard values?

Also, are you facing any Performance issues in the XI ABAP Stack ? If Not, whats the issue?

Howz the performance of the Java stack ?

If you want to proceed with setting up standard values for these parameters, please read note 830576.

Regards,

Hari Kishan

[Former Member]

Hi Hari,

Thanks for your reply, we not facing any performance issues right now. But, in EWA report is it is red and as per our customer requirement we have to raise the buffer quality to atlease 90%. Please tell me, in TOPAS command the available RAM memory is 1GB+, can we straight away increase the values of both parameters sga_max_size and db_cache_size .

I have go throughed the notes you mentined, but i couldn't get infor abt on what percent of RAM we should set these parameters. These parameters are set long back before database got increased and RAM was increased.

Regards,

Balaji Vedagiri

[Former Member]

Dumb questions

a) Why was it changed to less than default? Was the purpose to give memory to Java stacks?

b) Is there a performance issue now, XI is not a database heavy applicaton? If not why bother?

c) Why not change it back to default or to the same as QA?

[Former Member]

a) Why was it changed to less than default? Was the purpose to give memory to Java stacks?

Ans: These parameters are set long back

tell me how much RAM memory does the ABAP+JAVA stack occupy(minimum), as 90% of RAM is filled now.

b) Is there a performance issue now, XI is not a database heavy applicaton? If not why bother?

Ans: Currently there are not performance issues, but in EWA report it is RED and my customer wants it to increase the quality to atleast by 90%.

c) Why not change it back to default or to the same as QA?

Ans: As my analysis we need to increae the parameters by 1GB both means, the remaining RAM(1GB) will be filled means, my total RAM will filled this will lead to overall performance problem.

Regards

Balaji Vedagiri