Allocation of buffers for QSAM files
z/OS® DFSMS automatically allocates buffers for storing input and output for a QSAM file above or below the 16 MB line as appropriate for the file.
Most QSAM files have buffers allocated above the 16 MB line. Exceptions are:
- Programs running in
AMODE 24
. - Programs compiled with the
DATA(24)
andRENT
options. - Programs compiled with the
NORENT
option. EXTERNAL
files when theALL31(OFF)
runtime option is specified. To specify theALL31(ON)
runtime option, all programs in the run unit must be capable of running in 31-bit addressing mode.- Files allocated to the TSO terminal.
- A file with format-S (spanned) records, if the file is any of
the following ones:
- An
EXTERNAL
file (even ifALL31(ON)
is specified) - A file specified in a
SAME RECORD AREA
clause of theI-O-CONTROL
paragraph - A blocked file that is opened
I-O
and updated using theREWRITE
statement
- An