ABCs of z/OS System Programming Volume 3 - IBM Redbooks

Production batch refers to data created by specialized applications
(such as payroll), that can be critical to the continued operation of
your business or enterprise.
Test batch refers to data created for testing purposes.
VSAM data Data organized with VSAM, including VSAM data sets that are part of
an existing database.
Large data For most installations, large data sets occupy more than 10 percent of
a single DASD volume. Note, however, that what constitutes a large
data set is installation-dependent.
Multivolume data Data sets that span more than one volume.
Database data Data types usually having varied requirements for performance,
availability, space, and security. To accommodate special needs,
database products have specialized utilities to manage backup,
recovery, and space usage. Examples include DB2, IMS, and CICS
data.
System data Data used by MVS to keep the operating system running smoothly. In
a typical installation, 30 to 50 percent of these data sets are high
performance and are used for cataloging, error recording, and other
system functions.
Because these critical data sets contain information required to find
and access other data, they are read and updated frequently, often by
more than one system in an installation. Performance and availability
requirements are unique for system data. The performance of the
system depends heavily upon the speed at which system data sets
can be accessed. If a system data set such as a master catalog is
unavailable, the availability of data across the entire system and
across other systems can be affected.
Some system data sets can be system-managed if they are uniquely
named. These data sets include user catalogs. Place other system
data sets on non-system managed volumes. The system data sets
which are allocated at MVS system initialization are not
system-managed, because the SMS address space is not active at
initialization time.
Object data Also known as byte-stream data, this data is used in specialized
applications such as image processing, scanned correspondence, and
seismic measurements. Object data typically has no internal record or
field structure and, after it is written, the data is not changed or
updated. However, the data can be referenced many times during its
lifetime.
306 ABCs of z/OS System Programming Volume 3