Check data cache and procedure cache space with the total data cache
size configuration parameter.
Another way to determine how SAP ASE uses memory is to examine the memory-related messages
written to the error log when SAP ASE starts. These messages state exactly
how much data and procedure cache is allocated, how many compiled
objects can reside in cache at any one time, and buffer pool
sizes.
These messages provide the most accurate information regarding cache allocation on SAP ASE. The
amount of memory allocated for the procedure caches depends on the run value
of the procedure cache size configuration parameter.
Each of these error log messages is described below.
- Procedure cache – this error log message provides information about the procedure
cache:
server: Number of blocks left for proc headers: 629
- Proc buffer – a proc buffer (procedure buffer) is a data structure that manages compiled objects
in the procedure cache. One proc buffer is used for every
copy of a compiled object stored in the procedure cache.
When SAP ASE starts, it determines the number of proc
buffers required and multiplies that value by the size of a
single proc buffer (76 bytes) to obtain the total amount of
memory required.
- Proc header – while in the procedure cache, a compiled object is stored in a proc header
(procedure header). Depending on the size of the object to
be stored, one or more proc headers may be required. The
total number of compiled objects that can be stored in the
procedure cache is limited by the number of available proc
headers or proc buffers, whichever is less. The total size
of procedure cache is the combined total of memory allocated
to proc buffers (rounded up to the nearest page boundary),
plus the memory allocated to proc headers.
- Data cache – when SAP ASE starts, it records the total size of each cache and the size of each
pool in the cache in the error log. This example shows the
default data cache with two pools and a user-defined cache
with two
pools:
Memory allocated for the default data cache cache: 8030 Kb
Size of the 2K memory pool: 7006 Kb
Size of the 16K memory pool: 1024 Kb
Memory allocated for the tuncache cache: 1024 Kb
Size of the 2K memory pool: 512 Kb
Size of the 16K memory pool: 512 Kb