Determining the Default Data Cache Size

Both sp_cacheconfig and sp_helpcache display the current default data cache in megabytes.

For example, the following shows an SAP ASE that is configured with 19.86MB of default data cache:

sp_cacheconfig

Cache Name               Status     Type       Config Value    Run Value
------------------       --------   --------   ------------    ----------
default data cache       Active     Default    0.00 Mb         19.86Mb 
                                               ------------    --------
                       Total                   0.00Mb          19.86 Mb 
========================================================================
Cache: default data cache, Status: Active, Type: Default
       Config Size: 0.00 Mb, Run Size: 19.86 Mb
       Config Replacement: strict LRU, Run Replacement: strict LRU
       Config Partition:    1,   Run Partition:    1
IO Size       Wash Size     Config Size     Run Size      APF Percent 
--------      ---------     ------------    ----------    ----------- 
2 Kb          4066 Kb        0.00 Mb         19.86 Mb                10

To change the default data cache, issue sp_cacheconfig, and specify “default data cache.” For example, to change the default data cache to 25MB, enter:

sp_cacheconfig "default data cache", "25M"

This change is dymamic: you need not restart SAP ASE for the new value to take effect.

The default data cache size is an absolute value, and the minimum size for the cache size is 256 times the logical page size; for 2KB, the minimum is 512KB: for 16KB, the minimum is 4MB. The default value is 8MB. During an upgrade, SAP ASE sets the default data cache size to the value of the default data cache in the configuration file.