IMS/DB Overview for Applications Programmers

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 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 Environment Development will be performed using:

• IBM Mainframe

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.