IMS Essentials

Objectives
On successful completion of this course, attendees will be able to:

• describe the architecture of IMS batch and online systems
• analyse database and communication calls
• identify appropriate logical and physical database design features
• describe the structure of secondary indexes and logical relationships
• use IMS utilities to backup, restore, and reorganize the database
• discuss the facilities available in IMS to provide data integrity and system availability.
• trace the flow of a transaction through an IMS system

Who Should Attend
All those working in IMS Applications and Database Development, or any systems and operations personnel who require an understanding of the IMS environment.


Course Code
DISF
Contents
Introduction to IMS
Why Use a Database?; Database types; Hierarchical terminology; Processing path; Accessing data; Database implementation; IMS online environment; Message Format Services (MFS); Utilities; Logging; Operational responsibilities.


Introduction to Batch Programming
DL/I Language Interface; Program Specification Block (PSB); IMS Call Format; Function code; Record retrieval Workshop.


Advanced Database Programming
Update processing; Command codes; PCB Addressing; Boolean SSAs; Workshop.


Database Environment
Program Specification Block (PSB); PSB statements; PCB; PROCOPTs; PSB generation; ACB generation; PSB/program relationships; Batch JCL; Workshop.


Database Implementation - 1
DBD; Database Organisation and Access Methods.


Database Implementation - 2
Secondary indexing; Secondary data structure; Stand-Alone processing; Things to consider; Logical relationships.


Database Implementation - 3
An introduction to HALDB features and processing options.


Database Backup and Recovery
Logging; Image Copy; Reorganisation; Database Recovery Control (DBRC); associated tools and utilities.


IMS/TM Concepts & Facilities
IMS/DC configuration; Control (CTL) region; DL/I Separate Address Space (DLISAS); Database Recovery Control (DBRC); Message Processing Region (MPR); Batch Message Processing (BMP) region; Message scheduling; Logging.


IMS Online Programming - 1
Message Processing Program (MPP); Transaction codes & flow; Input message segment; Output message segment; IMS message calls; IO PCB mask; Common status codes; Workshop.


Message Format Services
MFS control blocks; DIF/DOF coding; MID/MOD coding; Attributes; Message management.


IMS Online Programming - 2
Alternate PCB; Using Alternate PCB; Transaction switching; Conversational programming; Using Checkpoint/Restart; Workshop.


Fast Path
General characteristics; Fast Path EMH; Data Entry Database (DEDB); Main Storage Database.


Online IMS System Recovery and Restart
Logging; Restart Data Set (RDS); Archiving; Contents of the Log; Normal restart; Emergency restart.


Sharing Data and Data Sharing
Sharing access - the problem; Sharing access - solutions; Control region / DLISAS; Program isolation; Locking; Deadlock resolution; Data sharing; Database-Level Sharing; Block-level sharing; DBCTL.


IMS Operations
Operational considerations; Operations planning; Starting IMS; Stopping IMS; Online change facility; Controlling IMS.


IMS Performance Management
DB performance; DB monitor; Database buffer pools; DC performance.