When the OPEN macro is called for a large format data set, it will
in many cases require the DCBE macro's BLOCKTOKENSIZE=LARGE option.
This requirement depends on the value of the BLOCKTOKENSIZE keyword
in SYS1.PARMLIB member IGDSMS
xx. The possible
values and their effects are:
- BLOCKTOKENSIZE(REQUIRE) in IGDSMSxx in SYS1.PARMLIB
- Every OPEN for a large format data set requires the BLOCKTOKENSIZE=LARGE
parameter on the DCBE macro, unless the data set contains no more
that 65␠535 tracks on each volume and the OPEN is either
for input using EXCP, BSAM or QSAM, or for update using BSAM or QSAM.
- BLOCKTOKENSIZE(NOREQUIRE) in IGDSMSxx in
SYS1.PARMLIB
- Applications can access large format data sets under more conditions
without having to signify BLOCKTOKENSIZE=LARGE on the DCBE macro.
The applications and data sets must meet any of the following conditions:
- The access method is QSAM or it is BSAM without the NOTE or POINT
macros.
- The access method is BSAM with the NOTE or POINT macros (MACRF=xP
is coded) and the data set has no more than 65535 tracks on the volume
and the OPEN option is INPUT or UPDAT.
- The access method is EXCP (MACRF=E is coded) and the data set
has no more than 65535 tracks on the volume and the OPEN option is
INPUT.
BLOCKTOKENSIZE(NOREQUIRE) is the default if that
system option is not specified.
OPEN will issue an ABEND 213-10 for large format sequential data
sets if the access method is not QSAM, BSAM, or EXCP. OPEN will issue
an ABEND 213-14, 213-15, 213-16, or 213-17 and EOV will issue ABEND
737-44 or 737-45 if the application program cannot access the whole
data set on the volume (primary, secondary, or a subsequent volume).