Db2 for z/OS: Operations & Recovery

This course provides attendees with a comprehensive introduction to the recovery of Db2 objects and the processes involved.
The course examines all the IBM-provided Db2 utilities and service aids, and discusses their involvement in recovery scenarios. Start-up, operation, and shut-down of the Db2 system is fully covered, to ensure attendees appreciate 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 discussed, such as out of sync. Log files, out of space datasets, and read/write errors on recovery datasets.

This course is available 'on demand' (minimum 2 students) for public presentations or for exclusive, one-company presentations.

What you will learn

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

  • list all of the major recovery components
  • use the Db2 utilities and service aids that are used in recovery situations
  • describe the actions to take 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, and the effect it will have on the Db2 system and data
  • explain the need for conditional restart and the effect it will have
  • set up a deferred or conditional restart
  • determine the effect conditional restart is likely to have upon data integrity
  • 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 designed for all those involved in the day to day operations and support of a Db2 for z/OS sub-system, as well as those responsible for recovery of Db2 objects and data.


While in-depth knowledge of Db2 is not required, a basic understanding of relational databases is assumed. Familiarity with TSO/ISPF is also required.


3 days

Fee (per attendee)

£1800 (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; Logging parameters - size & number of logs; logging parameters - checkpoints; Checkpoint records; Forcing an archive log.

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 Redo/Undo records; Deferred Restart:effect on committed UoRs, effect on in-flight UoRs; Delaying backout of long running tasks; Effect of delaying backout; Conditional restart; Conditional restart: control record, log truncation, limit restart, bypass backout, cold start, What's lost?, DSN1LOGP, cleaning up.

Problem Analysis & Handling

Basic code structure; Db2 subcomponents; Db2 control blocks; Page set structure; Problem handling; 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.

Db2 Physical Data Storage

VSAM file requirements; Creating VSAM files; Page sets; Page set structure; Index structure; Index keys & pointers; Data navigation; RIDS, pointers, and holes; Table row header format; Large Object data; Large Object columns; XML data; XML storage structure names.

Introduction to Db2 Utilities

Db2 utilities; Db2 utility packaging; Invoking online utilities - Db2i defaults panel; Invoking online utilities - Db2 utilities panel; Invoking online utilities - dataset names panel; Invoking online utilities - control statements panel; Control statements; LISTDEF control statement; Use of Wild Cards with LISTDEF; TEMPLATE control.

Utilities for Data Integrity

CHECK DATA utility; CHECK INDEX utility; CHECK LOB utility; REPAIR utility.

Utilities for Backup & Recovery

Backup & recovery components; COPY utility; COPY list of objects; COPY using LISTDEF and TEMPLATE; COPYTOCOPY utility; MERGECOPY utility; QUIESCE utility; RECOVER utility; RECOVER list of objects; Recovery involving referential integrity; Recovery and large objects: recover either to current point, recover either to prior point, recover both to prior point; Resetting status codes; XML data recovery; REBUILD INDEX utility; REPORT utility; MODIFY utility; BACKUP SYSTEM utility; RESTORE SYSTEM utility; Restoring to a specified point.

Other Online Utilities

LOAD utility; REORG TABLESPACE utility; Using shadow copies during REORG; REORG utility - BUILD2 phase; Shadow copies - FASTSWITCH; RUNSTATS utility; STOSPACE utility; UNLOAD utility.

Stand-Alone Utilities (service aids)

Invoking stand-alone utilities; DSN1COPY stand-alone utility; DSN1PRNT stand-alone utility; DSNJU004 (print log map) stand-alone utility; DSNJU003 (change log inventory) stand-alone utility; DSN1LOGP stand-alone utility; DSN1CHKR stand-alone utility; DSN1COMP stand-alone utility; DSNJLOGF stand-alone utility; DSNJCNVB stand-alone utility.

Catalog & Directory Recovery

Catalog / Directory recovery implications; Recovery sequence; Catalog & Directory point-in-time recovery; Recovery implications - DEFINE option; Recovery implications - FASTSWITCH; Recovery implications - identity columns & sequences; System-wide points of consistency.

What the students say

Human (and humane). Possibly a taller presenter would help but that's nitpicking.

Production support DBA

Aviva plc

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