Parameter CACHE_SIZE + MAXCPU

[Peer Hoelterhoff /cbs/]

Hi all,

im not quite sure about the parameter setting of CACHE_SIZE and MAXCPU. We
are running a maxdb 7.5.00 build 21 for an sap r/3 4.70 110. Both on a
single system with 2 processors with hyperthread (displayed as 4 processors)
and 2GB RAM.

The SAP system is allocated with 70% of the physical RAM - so i have 30% for
the database. Can i set all of this 30% to parameter CACHE_SIZE?

What is about with MAXCPU. The physical available CPU is diplayed as 4 but
we have only 2 processors with HT. Should i set MAXCPU therfor to 4 or to 2?

Best Regards, Peer

[Döhr, Markus ICC-H]

Post by Peer Hoelterhoff /cbs/
im not quite sure about the parameter setting of CACHE_SIZE
and MAXCPU. We are running a maxdb 7.5.00 build 21 for an sap
r/3 4.70 110. Both on a single system with 2 processors with
hyperthread (displayed as 4 processors) and 2GB RAM.
The SAP system is allocated with 70% of the physical RAM - so
i have 30% for the database. Can i set all of this 30% to
parameter CACHE_SIZE?

I would do it vice-versa, give the DB as much cache as possible (if you
application will still run then).

Post by Peer Hoelterhoff /cbs/
What is about with MAXCPU. The physical available CPU is
diplayed as 4 but we have only 2 processors with HT. Should i
set MAXCPU therfor to 4 or to 2?

We tested this extensively and we came to the conclusion that MAXCPU should
always be set to the number of _physical_ CPUs, or better said, the
_physical_ cores. Otherwise this may lead to locking situations.


Greetz,


SIEGENIA-AUBI KG
Informationswesen

i.A.

Markus Döhr
SAP-CC/BC, SAPDB-DBA

Tel.: [phone]
Fax: [phone]
E-Mail: ***@siegenia-aubi.com
Internet: http://www.siegenia-aubi.com