3. Installation › 3.3 Define Database Complex › 3.3.6 Set Up the CA MICS ISPF Environment › 3.3.6.1 ISPF LIBDEF Service Overview

3.3.6.1 ISPF LIBDEF Service Overview

The ISPF library definition (LIBDEF) Service lets you
logically modify the ISPF environment during the ISPF
session.  This makes it much easier for you to add new
applications, such as the CA MICS Workstation Facility, to
your installation's ISPF environment.

ISPF uses a series of libraries to access load modules
(programs), panels, messages, and tables.  These libraries
are opened when ISPF is started, and remain open until the
ISPF session ends.  Thus, all application load modules,
panels, messages, and tables must be included in the ISPF
environment allocated before ISPF is started.  However, the
LIBDEF Service lets you logically concatenate additional
libraries to the ISPF environment without leaving ISPF and
without reallocating the environment.

The LIBDEF service lets you define an application-level set
of libraries for ISPF panels, messages, tables, and programs.
LIBDEF adds libraries to the ISPF environment to be
searched BEFORE the original ISPF libraries.  For example, if
you use the LIBDEF Service for panels, the library that you
indicate is logically concatenated ahead of the original
ISPPLIB (panel library) data sets.

The ISPF program library, ISPLLIB, is a special case --
LIBDEF functions differently for the ISPLLIB allocation.  In
a production environment you will not normally have an
ISPLLIB allocation because your ISPF and PDF programs are
found in STEPLIB, the SYS1.LPALIB library, or the MVS link
list.  ISPLLIB is searched first and thus you can allocate a
new release of ISPF to ISPLLIB for testing.  But when you use
the LIBDEF service for ISPLLIB, your LIBDEF ISPLLIB is NOT
added to the ISPLLIB concatenation, but instead REPLACES the
original ISPLLIB allocation.  That means you lose access to
the original ISPLLIB allocation.  To retain program access
you must include your original ISPLLIB data sets in your
LIBDEF ISPLLIB allocation.  For example, you would allocate
both the CA MICS and new ISPF load libraries to your LIBDEF
ISPLLIB.  This technique is illustrated by sample 2 in
Section 3.3.6.2.