DATA
The DATA
option affects whether storage
for dynamic data areas and other dynamic runtime storage is obtained
from above or below the 16 MB line.
Default is: DATA(31)
Abbreviations are: None
For reentrant programs, the DATA
compiler
option and the HEAP
runtime option control whether
storage for dynamic data areas (such as WORKING-STORAGE
and FD
record
areas) is obtained from below the 16 MB line (DATA(24)
)
or from unrestricted storage (DATA(31)
). (DATA
does
not affect the location of LOCAL-STORAGE
data; the STACK
runtime
option controls that location instead, along with the AMODE
of
the program.)
Specify DATA(24)
for
programs that run in 31-bit addressing mode and that pass data arguments
to programs in 24-bit addressing mode. Doing so ensures that the data
will be addressable by the called program.
External data
and QSAM buffers: The DATA
option interacts with
other compiler options and runtime options that affect storage and
its addressability. See the related information for details.

- If DATA(24) is in effect and the LOC 31 phrase of the ALLOCATE statement is not specified, ALLOCATE acquires storage from below the 16 MB line.
- If DATA(31) is in effect and the LOC 24 phrase of the ALLOCATE statement is not specified, ALLOCATE will attempt to acquire storage from above the 16 MB line.

Making programs reentrant
Language Environment® Programming Guide (Using runtime options)
Allocation of buffers for QSAM files
RENT
ALLOCATE statement (Enterprise COBOL for z/OS Language Reference)