IBM Tivoli NetView for z/OS Programming: Pipes - IBM notice

Operand Descriptions
Usage Notes
PIPE QSAM
data definition name
Specifies what data definition name is to be used. If an initial (DD) or (DSN) is
not specified, the QSAM stage examines the specification. If the argument is a
single 1- to 8-character value without period delimiters or quotation marks,
then it is considered a data definition name. Otherwise, the argument is
considered a data set name.
You can use a data definition name with the QSAM stage by executing an
ALLOCATE command. A data set allocated in this manner can include a
member name as part of the specification. A data definition name that is
specified to QSAM with a member name is rejected. When using this method
for a device or medium that is not a data set, it must be suitable for Physical
Sequential access. Specify DSORG(PS) and a suitable block size.
data set name
Specifies what data set name is to be used. If an initial (DD) or (DSN) is not
specified, the QSAM stage examines the specification. If the argument is a
single 1- to 8-character value without period delimiters or quotation marks, it
is considered a data definition name. Otherwise, the argument is considered a
data set name.
(DD)
Specifies that the specification is for a data definition.
(DSN)
Specifies that the specification is for a data set name.
APPEND
Specifies that the data is to be appended onto the end of the records that are
already in the file (otherwise writing generally occurs from the start). APPEND
causes the DCB to be opened internally with the EXTEND option. Another
method for appending onto the end is to allocate the file using the MOD
keyword, in which case the QSAM APPEND option is redundant. See the
ALLOCATE command in the NetView online help or IBM Tivoli NetView for
z/OS Command Reference Volume 1 (A-N).
Do not use the APPEND option when writing to a PDS member.
v QSAM cannot access a data definition name and member name combination
except through a DDNAME allocated with a member name.
v When neither DD or DSN is specified, the QSAM stage examines the name
specification to determine whether it is a data set name or a data definition
name. This is the default.
v You can read and write to the same data definition or data set name within a
single pipe.
v Access security for the QSAM stage is provided through the READSEC and
WRITESEC commands. See the IBM Tivoli NetView for z/OS Administration
Reference for information on the READSEC and WRITESEC commands. Other
errors can stop processing before the security check can be done.
v The QSAM stage allocates the data set with DISP=SHR specified and then opens
the data set requesting OUTPUT access. It is possible for another application or
task to be writing or reading the data set at the same time as the PIPE QSAM
stage is reading or writing the data set. You might encounter this restriction
when two different QSAM stages are attempting to write to different members
Chapter 2. Pipeline Stages and Syntax 197