Re: SAP ASE Data Cache setup

Hi,

all in all you need a default data cache with 7644MB. So you have to configure this:

sp_cacheconfig "default data cache", "7644M"

go

If you receive an error message that you do not have sufficient memory, you have to increase the memory:

e.g. the error looks like this:

1>  sp_cacheconfig "default data cache", "7644M"

2> go

Msg 10879, Level 16, State 1:

Server 'JSX', Procedure 'sp_cacheconfig', Line 1733:

The current 'max memory' value '1792000', is not sufficient to change the size of cache 'default data cache' to '7644M' (7827456 KB). 'max memory' should be greater than 'total logical memory' '5410484' required for the configuration.

(1 row affected)

(return status = 1)

Then you have to reconfigure the memory (with the max memory parameter):

1> sp_configure 'max memory', 7410484

2> go

You can check the configuration with sp_cacheconfig.If you see a config value of 7644 MB (or more) for the default data cache you can continue.

Now we configure the 128k Bufferpool:

sp_poolconfig  "default data cache", "1500M", "128K"

go

An finally we're channging the wash area sizes:

sp_poolconfig  "default data cache", "128K", "wash=150M"

go

sp_poolconfig  "default data cache", "16K", "wash=614M"

go

Again you can use sp_cacheconfig to check the configuration:

1> sp_cacheconfig

2> go

Cache Name                                                               Status                           Type                             Config Value                                             Run Value

------------------------------------------------------------------------ -------------------------------- -------------------------------- -------------------------------------------------------- ------------------------------------------------

default data cache                                                       Active                           Default                            7644.00 Mb                                               7644.00 Mb

(1 row affected)

                                   ------------ ------------

                            Total    7644.00 Mb   7644.00 Mb

==========================================================================

Cache: default data cache,   Status: Active,   Type: Default

      Config Size: 7644.00 Mb,   Run Size: 7644.00 Mb

      Config Replacement: strict LRU,   Run Replacement: strict LRU

      Config Partition:            8,   Run Partition:            8

IO Size  Wash Size     Config Size  Run Size     APF Percent

-------- ------------- ------------ ------------ -----------

    16 Kb     628736 Kb   6144.00 Mb   6144.00 Mb     10

   128 Kb     153600 Kb   1500.00 Mb   1500.00 Mb     10

(return status = 0)

1>

Please monitor swapping / paging on OS - level; especially if you have increased the ASE memory with sp_configure "max memory".

Best regards,

Juergen