Target Audience

The course provides the COBOL or PL/1 designer or developer an overview of IMS/DB (DL/I). The course covers the use of IMS/DB, with lectures and demonstrations to ensure a high level understanding of the database.

Pre-requisites

A basic knowledge of COBOL or PL/1 would be advantageous.

Course Objectives

Whilst covering the basics of accessing IMS databases, this course also aims to give an insight into accessing IMS databases using batch COBOL or PL/1 programs. On completion of this course the student will be able to:

•     Understand hierarchical database structure
•     Understand the use of IMS control blocks
•     Understand Database Definitions
•     Understand Program Communication Blocks
•     Understand Program Specification Blocks
•     Understand the DL/1 'CALL' Statement and its' parameters
•     Understand the various DL/1 calls available
•     Understand Segment Search Arguments
•     Understand Command Codes

Course Environment

Development will be performed using:

•     IBM Mainframe

Course Details

INTRODUCTION TO IMS

An Overview of IMS

IMS/DB Database Management System

Hierarchical Databases

The Relational Model

IMS Recovery

IMS CONTROL BLOCKS

IMS Control Blocks

DL/I

Database Definition - DBD

DBD Parameters

Program Communication Block - PCB

PCB Parameters

Communication PCBs

Database PCBs

Program Specification Block - PSB

PSB Parameters

DBD, PSB and ACB Load Modules

IMPLEMENTING A DATABASE

DBDGEN

PSBGEN

Physical Database Definition

Loading Data

Testing

DL/1 PROGRAM EXECUTION

Using DL/1 with IMS/DC or CICS

Running a DL/1 Batch Program

Running a DL/1 Batch Message Program

THE APPLICATION PROGRAM

Program Specification Block

Program Communication Blocks

Database PCBs

Database PCB Mask

Executing the Application Program

The 'ENTRY DLITCBL' Statement

PROCEDURE DIVISION USING Statement

Accessing IMS Databases using DL/1

The 'CALL CBLTDLI' Statement

DL/1 CALL FUNCTIONS

What is a Call Function ?

Database Call Functions

GU - Get Unique

GHU - Get Hold Unique

GN - Get Next

GHN - Get Hold Next

GNP - Get Next Within Parent

GHNP - Get Hold Next Within Parent

ISRT - Insert

REPL - Replace

DLET - Delete

On-Line Call Functions

GU - Get Unique

GN - Get Next

ISRT - Insert

CHNG - Change

PURG - Purge

SEGMENT I/O AREAS

I/O Areas

I/O Area Size

I/O Segment Layout

Path Calls

SEGMENT SEARCH ARGUMENTS

General Use of SSAs

The Unqualified SSA

The Qualified SSA

The Boolean SSA

No SSAs

COMMAND CODES

The Null Command Code - *---

Concatenated Key - *C

Path Calls - *D

First or Last Segment Occurrence - *F or *L

Do Not Replace Segment - *N

Establishing Parentage - *P

Multiple Command Codes

DATABASE ORGANISATIONS AND ACCESS METHODS

Database Organisations

Hierarchical Indexed Sequential Access Method - HISAM

Hierarchical Indexed Direct Access Method - HIDAM

Hierarchical Direct Access Method - HDAM

FURTHER FACILITIES

IMS Utilities

Logical Databases

Secondary Indexes

Course Format

Practical sessions make up a large part of the course, allowing delegates to demonstrate and reinforce the lectures given. During these sessions the delegate will gain experience of writing COBOL or PL/1 batch programs to access IMS databases, using the parameters taught. The comprehensive Student Guide supplied is fully indexed serving as a useful reference tool long after the course has finished. Delegates will also be able to access a free help-line with technical questions relating to topics covered on the course.