How can I increase the data cache

[stephan_zehm]

hello experts,

im newbie to maxdb things. I´ve done the parameter check and i´ve got this sap recommendation:

*W1 Recommended value for data cache is at least 2997.77 MB, current value is 2897.29MB.

can you tell me where i can increase the data cache? I´ve looked for it in the Database Studio and i only found the parameter CacheMemorySize.

Thanks in advance

Nghia

[former_member229109 · Accepted solution]

Hello Nghia,

What is the version of your database?

Are you SAP customer?

CACHE_SIZE  or CacheMemorySize Name is dependent on the database version.

More information about the kernel parameters is available in the MaxDB documentation:

MaxDB Version 7.6:

http://maxdb.sap.com/doc/7_6/24/037f409cd50a1ae10000000a155106/frameset.htm

general database parameter:

CACHE_SIZE - Size of the I/O buffer cache (in pages)

As of MaxDB version 7.7.03 :

http://maxdb.sap.com/doc/7_7/44/bd1ec6a5d51388e10000000a155369/frameset.htm

Database Parameters, general database parameter:

CacheMemorySize - Size of the I/O buffer cache = data cache + converter (in pages)

Regards, Natalia Khlopina

[stephan_zehm · Accepted solution]

Hello Natalia,

thank you for replying,. the version of our database ist 7.8.2 PL 23

I´ve found that the CacheMemorySize - Size of the I/O buffer cache = data cache + converter (in pages is. So i increased the CacheMemorySize but I didn´t see any changes (see attachment). Should I restart the Database?

Regards, Nghia

[Former Member · Accepted solution]

Hi,

yes the parameter change of CacheMemorySize is only getting active after the database has  been stopped and restarted (db_offline -> db_online)

Using the following link you'll get recommendation about Configuration of your SAp System.
http://wiki.sdn.sap.com/wiki/display/MaxDB/Database+Configuration and Memory configuration:

http://wiki.sdn.sap.com/wiki/display/MaxDB/MaxDB+Memory+Sizing

Regards, Christiane