Db2 for z/OS: Operations

This course provides attendees with a comprehensive introduction to the operation of Db2 for z/OS systems. The course examines normal start-up, operation, and shut-down of the Db2 system, plus the additional steps that may be required following an abnormal termination. The need for deferred and conditional restarts is discussed, as are the methods of setting these up, and evaluating any additional work that may be required following the use of these methods. The diagnosis and resolution of other problems that may occur are also discussed, such as out of sync. Log files, out of space datasets, and read/write errors on recovery datasets.

What you will learn

On successful completion of this course you will be able to:

  • describe the actions taken during normal start-up, operation, and shut-down of the Db2 system
  • explain the actions to take during start-up following an abnormal termination
  • understand the need for deferred restart, how it is controlled, and the effect it will have on the Db2 system and data
  • explain the need for conditional restart, how it is controlled, and the effect it will have on the Db2 system and data
  • analyse any outstanding work following a conditional or deferred restart, and take the actions required to complete it
  • interpret common error messages, and decide upon the actions required.

Who Should Attend

This course is suitable for all those involved in the day-to-day operation of a Db2 for z/OS sub-system.


While in-depth knowledge of Db2 is not required, a basic understanding of relational databases would be beneficial. Familiarity with TSO/ISPF, JCL and operations in a z/OS environment is assumed.


1 day

Fee (per attendee)

£600 (ex VAT)


This includes free online 24/7 access to course notes.


Hard copy course notes are available on request from rsmshop@rsm.co.uk

at £50.00 plus carriage per set.

Course Code



Db2 Overview

Architecture overview; Working Storage Areas; Storage Pools; Buffer Pools; Db2 attachments; Logging & Recovery Data Sets; System databases; Db2 Objects; Object characteristics; SQL overview; Db2 Interactive (Db2i).

Db2 System & Operations

Issuing Db2 commands; Starting Db2; Phase 1: Log Initialisation; Phase 2: Current Status Rebuild; Phase 3: Forward Log Recovery; Phase 4: Backward Log Recovery; Processing log records; Controlling Lock Manager (IRLM); Controlling Distributed Data Facility; Controlling CICS attachment; Controlling IMS attachment; Db2 commands to control other resources; Stopping Db2.

Db2 Logging

Db2 logging; Unit of Recovery; Two-phase commit protocol; Active log parameters; Checkpoint parameters; Checkpoint records; Logging commands: SET LOG, DISPLAY, ARCHIVE.

Abnormal Termination & Restart

Db2 error messages & reason codes; Data integrity considerations; Log initialisation / Current Status Rebuild; Forward log recovery; Backward log recovery; In-doubt resolution; Processing log records; Deferred restart; Deferred restart: effect on committed UoRs, effect on in-flight UoRs; Limiting backout of long running task; Effect of delaying backout; Conditional restart; Conditional Restart Control Record; Conditional restart: log truncation, limit restart, bypass backout, cold start, what's lost?, DSN1LOGP, cleaning up.

Problem Analysis and Handling

Basic code structure; Db2 subcomponents; Db2 control blocks; Messages & codes; Basic dump analysis; identifying SQL statement; Diagnosis tools: traces, utilities; Possible problem areas; Active log out of space; Active log I/O errors; Archive log I/O errors; BSDS errors; Forced single BSDS mode; Recovering BSDS; Data errors; Down level datasets.

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