This hands-on course describes and explains the access method concepts in MVS and the structure and design of VSAM files. It teaches how to create VSAM files using the utility Access Method Services (AMS), both from a functional as well as a performance point of view.<br>Additionally, it provides the Systems Programmer and Operational Analyst with information on the structure of ICF catalogs and the related VTOC and Index VTOC.<br>Online exercises provide experience in creating, accessing and managing VSAM files. Attendees will create and use clusters, alternate indexes and paths.<br><br>This course is also available for one-company, on-site presentations and for live presentation over the Internet, via the Virtual Classroom Environment service.
Read more


Familiarity with basic z/OS principles and a working knowledge of TSO/ISPF and JCL.
Read more

Delegates will learn how to

  • describe and explain the concepts of the z/OS access methods
  • analyse the structure of the RRDS, ESDS, KSDS and LDS data sets
  • use the Access Method Services utility program IDCAMS to define, load, backup, monitor and manipulate VSAM data sets with particular emphasis on the KSDS file type
  • develop guidelines for optimised allocation of VSAM files for use at their installation
  • identify performance related issues in the batch and online environments that can be found when using the KSDS file type.
Read more


VSAM Overview

MVS and I/O processing; The access methods; The IOS Drivers; The I/O Supervisor (IOS); The Back-End process; MVS access methods; Queued Sequential Access Method; Basic Direct Access Method; Basic Partitioned Access Method; PDSE processing; And now to VSAM; VSAM features; Entry Sequenced Data Set (ESDS); Key Sequenced Data Set (KSDS); Relative Record Data Set (RRDS); Catalog concepts; ICF catalogs and VTOCS; ICF catalogs (BCS); VSAM Volume Data Set (VVDS); Cluster Catalog (BCS) entries; Alternate indexes and paths; VSAM overview - exercises.

VSAM Dataset Structure

Control Areas; Control Intervals; Control Interval structure; CI structure of fixed length records; CI structure of variable length records; Control Area structure ; elative Byte Address; Spanned records; Storage of data on DASD volumes; Entry Sequenced; Key Sequenced; Index component; Free space; RRDS characteristics; KSDS processing example; The Control Interval is rewritten; Deleting a record; Record insertion; CI split; CA split; VSAM dataset structure - exercises.

Using Access Method Services

Access Method Services (AMS); AMS command format; Example - define an ESDS; Modal commands; Cancelling IDCAMS steps; Using the ELSE and SET commands; Comments; Error messages; Dataset already exists.

Defining VSAM Datasets

IDCAMS commands; DEFINE command - main parameters; Defining a cluster; Cluster sub-parameters; IDCAMS required parameters; Space allocation and reuse; SHAREOPTIONs (x region, y system); Control Interval Size; More IDCAMS parameters; DATA and INDEX sub-parameters; Defining an ESDS; Defining an RRDS; Defining a KSDS; FREESPACE; DELETE MASK | NOMASK.

Listing Catalog Information

Listing catalog information - LISTCAT; Catalog information; LISTCAT; LISTCAT parameters; LISTCAT examples; LISTCAT output.

VSAM Dataset Management

VSAM data management commands; Loading datasets; REPRO; REPRO parameters; Copy ESDS to KSDS; Copy partial RRDS to RRDS; Copy keyrange from KSDS to KSDS; Merge two KSDSs; Copy KSDS to tape; Printing datasets; PRINT parameters; PRINT examples; PRINT output example - CHARACTER; Altering catalog entries; Deleting catalog entries; DELETE parameters; DELETE examples.

Alternate Indexes

Why use alternate indexes?; Alternate index design; Alternate index record; Defining a route to the base cluster; Update of an alternate index; Defining an alternate index; Alternate index sub-parameters; Alternate index (SMS); AIX record size calculation; Building an alternate index; Defining a Path; Printing a base KSDS; Printing via an alternate indexes using PATH.

VSAM Data Integrity

Data integrity; Disposition processing; VSAM SHAREOPTIONS; Cross system sharing; VSAM back-up options; The EXPORT command; VSAM recovery options; The IMPORT command.

VSAM Performance Considerations

What to tune; Record design considerations; Data CISZ and performance; CI% freespace; CI FSPC optimisation; Index CISZ considerations; Data CA size considerations; CA% freespace; Component level performance; VSAM buffers; Index component buffers; Optimum index buffering; Data component buffers; Optimum data component buffering; VSAM buffering techniques; VSAM NSR buffer utilisation; VSAM LSR buffer utilisation; Batch LSR; Is batch LSR the solution?; Batch LSR JCL changes; Additional BLSR SUBSYS parameters; BLSR recommendations; BLSR restrictions; AIX performance considerations.

Read more

Why choose QA

Dates & Locations

Frequently asked questions

See all of our FAQs

How can I create an account on myQA.com?

There are a number of ways to create an account. If you are a self-funder, simply select the "Create account" option on the login page.

If you have been booked onto a course by your company, you will receive a confirmation email. From this email, select "Sign into myQA" and you will be taken to the "Create account" page. Complete all of the details and select "Create account".

If you have the booking number you can also go here and select the "I have a booking number" option. Enter the booking reference and your surname. If the details match, you will be taken to the "Create account" page from where you can enter your details and confirm your account.

Find more answers to frequently asked questions in our FAQs: Bookings & Cancellations page.

How do QA’s virtual classroom courses work?

Our virtual classroom courses allow you to access award-winning classroom training, without leaving your home or office. Our learning professionals are specially trained on how to interact with remote attendees and our remote labs ensure all participants can take part in hands-on exercises wherever they are.

We use the WebEx video conferencing platform by Cisco. Before you book, check that you meet the WebEx system requirements and run a test meeting (more details in the link below) to ensure the software is compatible with your firewall settings. If it doesn’t work, try adjusting your settings or contact your IT department about permitting the website.

Learn more about our Virtual Classrooms.

How do QA’s online courses work?

QA online courses, also commonly known as distance learning courses or elearning courses, take the form of interactive software designed for individual learning, but you will also have access to full support from our subject-matter experts for the duration of your course. When you book a QA online learning course you will receive immediate access to it through our e-learning platform and you can start to learn straight away, from any compatible device. Access to the online learning platform is valid for one year from the booking date.

All courses are built around case studies and presented in an engaging format, which includes storytelling elements, video, audio and humour. Every case study is supported by sample documents and a collection of Knowledge Nuggets that provide more in-depth detail on the wider processes.

Learn more about QA’s online courses.

When will I receive my joining instructions?

Joining instructions for QA courses are sent two weeks prior to the course start date, or immediately if the booking is confirmed within this timeframe. For course bookings made via QA but delivered by a third-party supplier, joining instructions are sent to attendees prior to the training course, but timescales vary depending on each supplier’s terms. Read more FAQs.

When will I receive my certificate?

Certificates of Achievement are issued at the end the course, either as a hard copy or via email. Read more here.

Contact Us

Please contact us for more information