Determining the amount of memory Adaptive Server needs

The total memory Adaptive Server requires to start is the sum of all memory configuration parameters plus the size of the procedure cache plus the size of the buffer cache, where the size of the procedure cache and the size of the buffer cache are expressed in round numbers rather than in percentages. The procedure cache size and buffer cache size do not depend on the total memory you configure. You can configure the procedure cache size and buffer cache size independently. Use sp_cacheconfig to obtain information such as the total size of each cache, the number of pools for each cache, the size of each pool, and so on.

Use sp_configure to determine the total amount of memory Adaptive Server is using at a given moment:

1> sp_configure "total logical memory"
Parameter Name        Default   Memory Used   Config Value   Run Value
   Unit               Type
--------------        -------------- --- ----------- ------------ ---------
-------------------- ----------
total logical memory  33792    127550         63775         63775
   memory pages(2k)   read-only

The value for the Memory Used column is represented in kilobytes, while the value for the Config Value column is represented in 2K pages.

The Config Value column indicates the total logical memory Adaptive Server uses while it is running. The Run Value column shows the total logical memory being consumed by the current Adaptive Server configuration. Your output differs when you run this command, because no two Adaptive Servers are configured exactly the same.

See the Reference Manual: Procedures.