VSAM Training Services Computer Education Professionals

VSAM Training Services

Submit VSAM Questions

Contact You

SYS-ED/M - Mobile Devices

VSAM Training Services Advanced search

Knowledge Base


Web Browser Viewing - MS Edge

VSAM Performance

Structure and Strategies

VSAM System Software VSAM: Advantages VSAM Dataset Comparison
VSAM Training by SYS-ED Courseware for Teaching Professional Distance-learning Service
VSAM Components: Memory, Usage, and Allocation IBM VSAM Integrated Mainframe Training Environment Mainframe Training Programs







VSAM, CICS, Db2, DB2, IBM MQ, IMS, TSO/ISPF, and z/OS are registered trademarks of IBM Corporation.
Courseware for Teaching - VSAM Training
Courseware for Teaching
Cloud Programming - 2018
Open Source Software GSA Submission

VSAM Language Specific Application Maintenance

VSAM System Software

In the IBM mainframe environment an access method is required for an application program written in a procedural or low-level language to access data on a DASD: Direct Access Service Device. The role of an access method includes setting record size, determining available disk space for record storage, writing data to disk, locating data on disk, and retrieving data from the disk. Without a reliable access method, the programmer would be required to make calculations and write the code in each program. The VSAM code in legacy programming languages - primarily COBOL, Assembler, and PL/1 - is a component of operational infrastructure specific to the client's IBM mainframe operating system - z/OS, z/VM, or z/VSE. VSAM is applied differently with each operating system and the programming language provides the syntax for processing VSAM files.

IBM Mainframe Software Environment

VSAM - Programming Languages

In the late 1970ís IBM introduced VSAM: Virtual Storage Access as its new access method; replacing ISAM and BDAM. VSAM added functionality, device independence, and improved performance. It also was easier to use. Improvements have been made to VSAM and it is still integral mainframe system software. VSAM is used in the CICS Transaction Server environment for recoverability, data locking, and integrity to source data. Sharing of VSAM data among CICS regions is done with VSAM RLS: Record-Level Sharing; this adds record caching and record locking. Logging and commit processing remains the responsibility of CICS. Sharing VSAM data outside a CICS environment will be restricted. The IBM DFSMS Transactional VSAM Services - DFSMStvs product allows the sharing of VSAM datasets across CICS, batch, or distributed systems. DFSMStvs permits concurrent shared updates of recoverable VSAM datasets by online transactions and batch applications.

VSAM is an access method for IBM system software products: IMS, CICS, and Db2. Although the role of VSAM and its relative importance has changed with the emergence of Db2 and web enablement technologies, a knowledge of VSAM is important for optimizing performance and balancing the processing of input/output.

VSAM has applied advancements in hardware technology to improve parallel processing performance. In a multi-extent multi-volume VSAM dataset, sequential access processing does not allow for any type of parallelism for I/O operations among the volumes. When an I/O operation is executed for an extent in a volume, no other I/O activity from the same task or same dataset is scheduled to other volumes. In a situation where I/O is the major bottleneck and there are available resources in the channel subsystem and controllers, it is an efficient use of resources.

Data striping addresses this sequential access performance problem by adding two modifications to the data organization.

  • The records are not placed in key ranges along the volumes; instead organization is in stripes.

  • Parallel I/O operations, in the form of control intervals, are scheduled to sequential stripes on different volumes.

Enhancements were made to VSAM with the IBM z/OS V1.10 operating system. The VSAM CA: Control Area Reclaim capability provides applications which use VSAM KSDS: key-sequenced datasets with improved availability through minimizing outages required for data defragmentation and reorganization. Disk space utilization also is better. SYS-ED has been evaluating IBM product announcements regarding performance and reports of a 44% improvement for VSAM-based workloads. IBM z/OS 2.x operating system supports VSAM record-level sharing in a sysplex environment to improve catalog sharing, reduce contention, and efficient coupling facility caching to deliver high throughput and performance.

VSAM z/VSE provides enhancements to chained RPL support and removal of duplicate VOLSERs on DEFINE CLUSTER statements. Chaining VSAM requests can be used in VSE/VSAM applications to save significant system overhead. During initialization in Record Management, all RPLS: Request Parameter Lists in the chain are frozen. With z/VSE 5.2 and higher, the entire RPL chain will be released if an error is detected in one RPL in the chain.

VSAM: Advantages

There are advantages in working with VSAM datasets: key-sequenced, entry-sequenced, or relative-record. Access within the dataset is achieved by a record key, relative address, or relative record number. An individual record is addressed through displacement, in bytes, from the beginning of the dataset.

Device Independence
VSAM is direct access storage device independent. A record is addressed using the displacement of the record from the beginning of the dataset. There is no requirement for information specific to the storage medium. There can be physical distribution of data across DASD packs.

High Performance
VSAM is a high performance access method for rapid insertion of records and minimal reorganization; this is derived from the organized index and distributed freespace. It also can be configured to reduce DASD access movement and rotational delay. Deleted record space is reclaimed.
Datasets can be shared between read-only regions. There are options for specifying diagnostic aids and printed-output

Simplicity of Use
All VSAM datasets are cataloged; JCL: Job Control Language parameters are used for defining datasets. IDCAMS commands can be invoked using TSO commands. VSAM datasets are used in in CICS programs. There is built-in data security including password protection.

Central Control
The VSAM catalog consolidates information about datasets and storage space. Access Method Services controls the definition and deletion of datasets and the catalog information.

Recovery of Data
VSAM catalogs can be defined for recovery of data. Recovery is based on information recorded on within the volumes and controlled by the catalog.

Portability of Data
VSAM provides for portability among IBM mainframe systems. The VSAM record format is standard to IBM operating systems.

There are disadvantages associated with VSAM.  The primary key cannot be changed for a KSDS.  KSDS and RRDS datasets must reside on DASD.
VSAM datasets cannot be browsed or edited using standard ISPF tools.

VSAM Dataset Comparison

The simple design of VSAM made it applicable to many applications.

Sequence of data records Primary Key Entry Relative Record Number
Type of access Sequential or Direct Key or RBA Sequential or Direct RBA Sequential or Direct Relative Number
Record format Fixed, Variable, Spanned Fixed, Variable, Spanned Fixed
Use free space to: Insert and Update. Not used. Not used.
Add new records Anywhere EOF At specified slots.
Change record size Yes No No
Delete record Yes. Space is reused. No Yes. Slot is set to x'00'.
Alternate index Yes Yes No

In modern information technology, there are advantages in using a database instead of or in conjunction with VSAM datasets; this includes tools and querying capabilities.

VSAM Training by SYS-ED

Since 1980, SYS-ED has been a leader in VSAM training and educational consultancy. We have a track record for developing the knowledge and skillset required by Fortune 1000 companies government municipalities, healthcare providers, and consulting firms to address specific operational objectives. If your organization outsourced the optimization of its VSAM coding to consulting firms in the 1980ís, it more than likely was SYS-ED which trained the personnel that did the actual work.

The sample programs and exercises were developed, updated, and tailored to teach VSAM in MVS | z/OS and DOS/VSE | z/VSE environments with legacy programming languages. The original SYS-ED VSAM student handout served as a framework from which industry standard textbooks were developed - subject matter, examples, and exercises - to meet work environment operational requirements. When information technology professionals attend a SYS-ED VSAM course, they have the documentation, skeleton programs, training aids, and supervised hands-on instruction to code and maintain programs back on the job.

IBM's information agenda is built on its proprietary operating systems and system software. Its foundation is to simplify, collaborate, reuse, and standardize.

1- Delivery of content through multiple delivery medium as part of a collaborative environment for integrating data at a business level.

2- Student handouts, reference guides, and validation assessment that leverage existing investments in software infrastructure.

3- Application development accelerators in the form of industry and client-specific training aids, examples, templates, and data modeling.

4- Support services in the form of technology updates, knowledge base, answers to questions, and tailored documentation in hybrid and interrelated information technology.

SYS-ED's mainframe course offerings, training programs, and software specific websites have been designed to augment the IBM strategy. The value added service to a SYS-ED VSAM course is the specialized training. Clients are encouraged to provide listcats from their production systems prior to attending a class. We analyze and interpret that information and teach the concepts and techniques required to make VSAM performance optimization a reality. In addition to VSAM, SYS-ED provides training on the IBM and third party mainframe utilities and development tools with integrated exercises on Compuware and Computer Associates software.

Case and point, if your organization outsourced its CICS and VSAM coding and program maintenance to consulting companies in the 1980ís, it more than likely was SYS-ED which trained the consultants who did the actual design and coding.

CICS Transaction Server COBOL
Db2 Relational Database VSAM Performance and Tuning

Upon completion of a instructor-led course at the client location, it is standard policy to organize content for future use in a web-based training infrastructure.

Courseware for Teaching

The courseware used in SYS-ED courses consists of student handouts, training aids, and industry-specific examples and exercises. The CETi knowledge base aggregates and analyzes information in the public domain. Content is added selectively to courseware. The long term strategy is to have our courseware recognized as a NRV: Nationally Recognized Vendor.


VSAM Training Services

VSAM: Virtual Storage Access Method
Mainframe Utilities and Development Tools
Programming Skills
COBOL Language and Application Development
Legacy Programming Languages

CICS Transaction Server Programming
IMS Programming
Db2 Programming

Web-based Training Services

Technology Driven IT Training Teaching Models: Return on Investment Web-based Training Services

SYS-ED's VSAM courseware is updated with information from CICS Transaction Server and IMS Transaction Server technology updates and assessments and CFAQs: course frequently asked questions. Given the scarcity VSAM textbooks, an organized sequential presentation of subject matter with performance and workshop objectives indexed for reference is important for effective teaching.

Professional Distance-learning Service

The distance-learning service is an extension of the SYS-ED schedule, inclusive of courseware and training aids. A distance-learning course is 65% lecture with pre and post course validation, review questions, examples, workshops, and website support services.

VSAM Training - New York State Department of Education Standards

Enrollment requires a consultation with the manager sending the employee for the training. The prospective trainee needs to be qualified for the course and service transmission to the client location tested: bandwidth, firewall, base operating system, software requirements, web browser, and set-up of hands-on machine exercises. SYS-ED reserves the right to deny enrollment in its courses.

Industry Standard VSAM Training Service

There have been inquiries regarding whether SYS-ED still offered VSAM training for IT professionals.

Selection of Delivery Medium Mainframe Environment Experience

Instructor-led VSAM Training VSAM Training Services
Delivery Medium and Private Courses - Alternative to Source Software Companies
Delivery Medium Alternative to IBM for Mainframe Training
COBOL Language Mainframe Utilities and Tools VSAM CICS Transaction Server IMS Transaction Server

The typical comments were that:

1.It is extremely to find VSAM training for specific development and maintenance tasks.
2. There is a scarcity of VSAM for Programmers and VSAM Performance and Optimization courses, 3 days or fewer in duration, geared to  legacy programming languages in IBM mainframe operating systems.
3. A high percentage of VSAM courses are cancelled.
4. Travel costs and living expenses in a majority of situations are a significant constraint when it comes to attending a VSAM course.
5. It is important to have a resource for asking VSAM questions once the VSAM training is complete.

In response to these questions:

VSAM Training Services Yes, SYS-ED offers multiple levels of VSAM training: z/OS and z/VSE.
VSAM Training Services Yes, since 1980, SYS-ED has taught standalone VSAM courses and as part of mainframe training programs.
VSAM Training Services We have the flexibility and resources to conduct personalized training.
VSAM Training Services VSAM courses are available in multiple formats: distance-learning, blended web-based delivery, and classroom.
VSAM Training Services Upon completion of a SYS-ED course, our staff is available to answer VSAM questions.

SYS-ED has been conducting courses in the public domain since 1980; however, there have been changes in the laws and regulations governing computer training in the state of New York. The schedule on our websites reflects a projected time frame for licensure with the New York State Department of Education - Bureau of Proprietary School Supervision and submission and approval of curriculum. It will be updated quarterly.

VSAM Components: Memory, Usage, and Allocation

VSAM tuning consists of providing a satisfactory level of service from a system at an acceptable cost. It can be achieved by providing sufficient buffers to minimize physical I/O and allowing concurrent operations on the datasets. Knowledge of buffer location, number, and size and the use of multiple index and data buffers are required for determining a VSAM database turning strategy.

    LSR: Local Shared Resources     NSR: Nonshared Resources     Hiperspace Buffers     RLS: Record Level Sharing    
    BUFFERS     INDEXBUFFERS     HSDATA     VSAM Server, Subsystem SMSVSAM    
    Strings     DATABUFFERS     HSINDEX     Sharing Control Datasets    
          Strings           Common Buffer Pools and Control Blocks    

The cost for concurrent operations on datasets are the additional virtual and real storage required for the buffers and control blocks. Knowlege of component software and memory allocation associated with the dataset type are used for implementing an efficient optimization of VSAM.

IBM VSAM - Integrated Mainframe Environment Training

z/OS: Job Control Language and Utilities Xpediter /TSO - Compuware Abend-AID - Compuware COBOL Debugging with Abend-AID- Compuware Xpediter /CICS - Compuware Legacy Programming Languages

VSAM - z/OS and Compuware File-AID Training

File-AID: Batch - Compuware File-AID: TSO - Compuware File-AID for Analysts - Compuware File-AID: IMS - Compuware File-AID: Db2 - Compuware File-AID/RDX (Db2 - Compuware

Mainframe Training Programs

SYS-ED offers entry-level and client-specific mainframe training programs.

An entry-level mainframe training program is comprised of the z/OS operating system, programming skills, programming language, and system software. These programs have been developed and taught over a quarter century.

Entry Level Mainframe Assembler Language COBOL Language
PL/1 Language z/OS Operations and System Programming CICS Transaction Server

Client-specific mainframe programs are a prioritized sequencing of component courses: topics, duration, examples, exercises, and project specifications as part of the job training workshops. This also can include an integrated case study.

The recommendation is that a training program have pre and post-course assessment, lesson review questions, and a record kept of completed assignments. At the client discretion, a grading system can be applied to the student work.

Evolving IT - Interrelated Technologies

Organizational enterprise has a substantial investment in IBM mainframe hardware, system software infrastructure and applications specific to their business model. However, there are public, private and hybrid cloud processing and web-enabled development alternatives that may be less expensive than legacy mainframe transaction processing: Amazon Web Services, Google Cloud Platform, and Microsoft Azure. IBM has its own SoftLayer cloud  computing platform and supports both the OpenStack and Cloud Foundry open source standards. There will be long term implications on whether to maintain and upgrade the existing legacy applications, many of which are now thirty or more years of age. The programmers who developed and maintained CICS and IMS Transaction Server applications using VSAM are reaching retirement age.

SYS-ED trained a significant portion of the first generation of DP personnel. And looks forward to training their IT successors in the 21st century.

IBM Tools Maintenace Programming and SOA Enterprise COBOL

VSAM Training Services

VSAM Courses
SYS-ED's VSAM courses are tough, but they're worth it. Our challenging VSAM training is for Fortune 1000 companies, government municipalities, healthcare providers, software houses, and consulting companies to meet their staffing requirements and acquire specialized VSAM skillsets.1

SYS-ED's mainframe service draws upon a library of student handouts, sample programs, exercises, and case studies to teach VSAM with legacy programming languages in the z/OS, z/VM, and z/VSE operating system environments.

Teaching is Our Business
Most computer training companies are divisions of large software companies or consulting companies. Not SYS-ED. Our only goal is to provide VSAM training for motivated IT professionals. This independence allow to concentrate on teaching.

Our Teachers Know How to Teach
SYS-ED instructors combine teaching skills with VSAM experience in the IBM mainframe environment - operating systems, programming languages, utilities and development aids, and system software. After a course, they are available to answer questions.

Enrollment - SYS-ED VSAM Courses are Not for Everyone
No one is allowed to enroll in a SYS-ED mainframe course without a consultation with our Director of Education. We review the operational objectives and project specifications for the organization evaluating whether to send its employee for the training. The employee only is allowed to enrolls if they have the background corresponding to the course.

VSAM Training - Distance-learning or at Your Office
SYS-ED VSAM courses are provided over the Internet through a distance-learning delivery medium or classroom instruction. Client location courses can include the same workshops and case studies as through the SYS-ED schedule.

Technology Exchange Websites

SYS-ED's websites compile, organize, and present software specific and established operational categorizations of information technology. They provide a framework for assessing knowledge transfer: web-based training, classroom instruction, courseware, learning paths, and validation assessment.


www.cicstrainingbysysed.us www.coboltrainingbysysed.us www.db2trainingbysysed.us
www.imstrainingbysysed.us www.mainframetrainingbysysed.us www.mfutilitiesandtoolsbysysed.us
www.mqseriestrainingbysysed.us www.programmingbysysed.us www.sastrainingbysysed.us

Footnote 1:
SYS-EDís core VSAM curriculum have been submitted to the New York State Department of Education - Bureau of Proprietary School Supervision for technical review and licensing.