A data set definition is a Jazz™ model
object that is stored in the Rational Team Concert™ for System z® Jazz repository. It contains all the information
that is related to a given data set on a z/OS® system. Every data set that a build process
references must correspond to a data set definition, including:
- Temporary, working data sets used by compilers, such as the SYSUT
files that a COBOL compiler uses.
- Permanent data sets that will represent project artifacts.
- Unmanaged data sets like language environment partitioned data
sets that are included in a SYSLIB concatenation.
A data set definition contains the following information:
- The name of the data set
- A usage type that indicates whether the data set definition is
for a zFolder data set, a new data set, an existing data set, or a
temporary data set
- The physical attributes that are required to create a data set
- A data set type. This can be either a partitioned data set extended
(PDSE), or, in the case of a temporary or a new data set, unspecified.
- An optional member name
Remember: A data set definition makes no statement
about the actual existence of a data set on a particular build system.
It is simply a container for information about a data set.
When the data set definition is combined with information from a build
request, such as the target system and a high-level qualifier (HLQ),
you can allocate a new data set with the characteristics you specify
in that data set definition.
A build process uses a data set
definition four ways:
- As a reference to a data set and, optionally, to a member that
already exists in the z system; for example, data sets containing
system libraries supplied by CICS® or
COBOL language environment (LE) system libraries.
- As a new permanent data set, wherein you specify the data set
characteristics required to create a data set.
- As a temporary data set, wherein you specify the data set characteristics
required to create a data set. In the Translator portion of the Data
set definition allocations table, set the temporary flag in the Keep
column to indicate that this data set should be deleted before job
processing ends.
Note: You can improve system performance by eliminating
much of the overhead and time required to move data physically between
main storage and an I/O device if you use Virtual Input Output (VIO)
devices for temporary data set allocation. To take advantage of this
option, specify VIO as the Generic Unit parameter
in the temporary data set definition.
- As a reference to a data set extended by a zFolder. When you create
a new zFolder in a zComponent Project, you will associate a data set
definition with that zFolder. When the build process references this
container, the data set is allocated based on the attributes you set
in the data set definition.