Moving Space from Other Memory Pools

To transfer space from another pool specify the cache name, a “to” I/O size, and a “from” I/O size.

This output shows the current configuration of the default data cache:

Cache Name               Status    Type     Config Value Run Value
------------------------ --------- -------- ------------ ------------
default data cache       Active    Default      25.00 Mb     29.28 Mb
                                            ------------ ------------
                                     Total      25.00 Mb     29.28 Mb
=======================================================================
Cache: default data cache,   Status: Active,   Type: Default
     Config Size: 25.00 Mb,   Run Size: 29.28 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   3844 Kb      0.00 Mb     18.78 Mb     10
    4 Kb    512 Kb      2.50 Mb      2.50 Mb     10
   16 Kb   1632 Kb      8.00 Mb      8.00 Mb     10

To increase the size of the 4K pool from 2.5MB to 4MB, taking the space from the 16K pool:

sp_poolconfig "default data cache","4M", "4K","16K"

This results in:

Cache Name               Status    Type     Config Value Run Value
------------------------ --------- -------- ------------ ------------
default data cache       Active    Default      25.00 Mb     29.28 Mb
                                            ------------ ------------
                                     Total      25.00 Mb     29.28 Mb
=======================================================================
Cache: default data cache,   Status: Active,   Type: Default
     Config Size: 25.00 Mb,   Run Size: 29.28 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   3844 Kb      0.00 Mb     18.78 Mb     10
    4 Kb    512 Kb      4.00 Mb      4.00 Mb     10
   16 Kb   1632 Kb      6.50 Mb      6.50 Mb     10

When you move buffers between pools in a cache, SAP ASE. It cannot move buffers that are in use or buffers that contain changes that have not been written to disk.

When SAP ASE cannot move as many buffers as you request, it displays an informational message, giving the requested size and the resulting size of the memory pool.