This Natural profile parameter can be used to set the minimum size of the
local data buffer (DATSIZE).
Alternatively, you can use the equivalent Natural profile parameter
DS or macro
NTDS (see
Using Optional Macros in a Natural Parameter
Module in the Operations
documentation) to specify the DATSIZE value.
| Possible settings | 10-2097151 |
Minimum buffer size in KB. |
|---|---|---|
| Default setting | 32 |
|
| Dynamic specification | yes | |
| Specification within session | no |
The DATSIZE buffer is a "variable size" buffer.
If more storage for local data areas is required during the session, the
DATSIZE buffer is expanded dynamically. In a thread environment,
the DATSIZE may be temporarily allocated outside the storage
thread if it becomes too large. The size of the DATSIZE buffer is
reduced back to the minimum size when the application does not need the space
any longer.
At execution time, the DATSIZE buffer holds the
local data used by the Natural main program being executed and the local data
of all subordinate objects (except "FETCHed" programs) invoked by
this program.
When you use Natural in a development environment, the minimum
DATSIZE required is the default setting (that is, 32
KB). A smaller DATSIZE is only possible when using
Natural as a runtime-only environment without any Natural utilities being
available.
The actual DATSIZE requirement can be calculated
as follows (refer to the illustration below):
If another object is invoked by the main program, the local data of this
object are also held in the DATSIZE buffer.
If other objects are invoked from the invoked object (with a
CALLNAT,
PERFORM,
FETCH RETURN,
INPUT USING MAP
statement, a helproutine/helpmap being invoked), their local data are also held
in the DATSIZE buffer; the local data of an invoked object is held
in the DATSIZE buffer until control is returned from the invoked
object to the invoking object.
If another main program is invoked with a FETCH statement, the local data
of all previously invoked objects are deleted from the DATSIZE
buffer and the local data of the "FETCHed" program are held in the
DATSIZE.
In addition, an amount of approximately 128 bytes of general control
information for execution are held in the DATSIZE buffer, plus
approximately 128 bytes of control information for each object whose local data
are being held in the DATSIZE buffer. This is illustrated in the
figure below.
The system command LIST provides an option to
display directory information about an object. This information includes the
object's DATSIZE storage requirement (not including the control
information).
