High-level procedure for defining program views with DDL

You define new IMS program views by CREATE PROGRAMVIEW DDL statements. You alter IMS program views by using the DROP PROGRAMVIEW and CREATE PROGRAMVIEW DDL statements.

A program view, also known as a program specification block (PSB), must be created before you execute an application program under IMS. The program view is used to describe the program and its use of logical terminals and logical data structure.

A program view cannot be altered. Instead, you can DROP and then ADD a PSB. For example, if you want to add, drop, or delete a schema (PCB) from a program view, you need to drop the PSB, then recreate it with the PCB/schema included that you need.

You define the characteristics of an application program by using the CREATE PROGRAMVIEW statement. At least one is needed for each message, batch, or Fast Path program. The name of the program view and its associated application program must be the same in a telecommunications system.

The CREATE PROGRAMVIEW statements describe the IMS resources to be used through a list of schemas, also known as program communication blocks (PCBs).

If you are creating a new database with a CREATE DATABASE statement, create a program view within the same DDL commit scope, so that the database is useable.

Recommendation: Use the IMS Enterprise Suite Explorer for Development to create or modify database and program view definitions and submit them to IMS. Using IMS Explorer for Development, you can create new database and program view definitions from the existing databases and program views in your IMS system and then modify the definitions as necessary.

Procedure

To create a new program view:

  1. Code your DDL statements.
    1. If you are modifying an existing program view, include a DROP PROGRAMVIEW statement.
    2. Define the program view by coding the CREATE PROGRAMVIEW, CREATE SCHEMA, and CREATE SENSEGVIEW statements.
    3. Include a COMMIT statement as the final statement.
  2. Submit the DDL statements to IMS by using either the IMS Enterprise Suite Explorer for Development or the IMS SQL Batch utility.
    Upon receiving the DDL with a COMMIT statement, IMS takes the following action:
    • Validates the DDL syntax and confirms that the program view does not already exist.
    • Updates the PSB record in the IMS catalog
    • Generates the required application control blocks (ACBs) and stores them in the staging data set of the IMS directory.
    • Updates the resource list indicating this program was updated.
  3. Issue the IMPORT DEFN SOURCE(CATALOG) command to activate the program view definitions. IMS activates the pending change in the catalog.
    If you are adding program views only, you have can activate the program views on a subset of IMS systems. For more information, see Activating PSBs in subsets of systems in an IMSplex.

To modify an existing program view:

  1. If your installation maintains PSB, DBD, and ACB libraries, update the libraries to reflect the new or modified program views by using the IMS Catalog Library Builder utility (DFS3LU00).