IBM SS83G - z/OS VSAM and Access Method Services

Course Outline

Introduction to VSAM data sets

• describe the structure, organization, and use of VSAM clusters
• explain the function of Control Intervals (CI) and Control Areas (CA)
• describe the purpose of CI splits and CA splits and how they are accomplished
• estimate DASD space requirements for various cluster types

ICF catalogs

• discuss the use of the ICF catalog
• describe the structure, purpose, and basic contents of the master catalog
• describe how the master catalog is located at initial program load (IPL) time
• discuss the structure, purpose, and basic contents of user catalogs
• create the ICF catalogs
• describe the catalog search
• discuss and create the two types of alias

IDCAMS commands, part 1

• discuss the IDCAMS program
• code the JCL to run IDCAMS
• code the DEFINE CLUSTER command to create specific VSAM data set organizations
• code the LISTCAT command to format and print entries from the catalog

JCL for VSAM

• explain creation and deletion of VSAM clusters using JCL and the DFSMS data class facility
• describe the additional JCL parameters that support VSAM clusters
• discuss the purpose of data class
• explain the assignment of data class through JCL and the Automatic Class Selection (ACS) routines

IDCAMS commands, part 2

• describe the function of REPRO, PRINT and DELETE commands
• use REPRO to load and back up a VSAM cluster
• use PRINT to print a VSAM cluster in various formats
• use DELETE to remove the catalog entry for the data set and scratch the data set from the volume
• describe and code modal commands to provide for conditional execution of Access Method Services (AMS) statements

Buffering

• explain how buffer space may impact performance either positively or negatively
• explain the use of data and index buffers in sequential processing and direct processing
• evaluate the use of JCL Access Method Parameters (AMP) keywords to manage buffers
• code the buffer keywords on the Dataset Definition (DD) statement

VSAM integrity and security

• explain how integrity and security is maintained
• discuss the meaning and use of SHAREOPTIONS
• discuss the need for serialization of updates to a data set
• describe how ENQ/DEQ macros are used to serialize data set updates in multiregion and multisystem environments
• explain the impact of buffering and SHAREOPTION modifications
• explain VSAM record level sharing
• use the VSAM integrity and security options: RECOVERY, ERASE, VERIFY, and passwords
• compare VSAM passwords with Resource Access Control Facility (RACF) security

Tuning

• explain the use of CI and CA FREESPACE
• discuss the performance impact of cache
• describe the space allocation process with KEYRANGES and multivolume data sets
• explain the contents of an Index CI
• explain how VSAM key compression works

IDCAMS ALTER

• explain the basic functions of the ALTER command
• code the ALTER command to modify options for processing existing VSAM objects
• code the ALTER command to modify options for buffering, FREESPACE, SHAREOPTIONS and passwords

Alternate indexes

• describe the reasons for using an alternate index
• discuss the basic contents of an alternate index
• use a PATH to process base cluster records directly and in alternate key sequence
• define and load an alternate index
• explain the impact of SHAREOPTIONS when opening a base cluster and associated alternate indices
• explain programming and JCL considerations

Advanced functions and extended format data sets

• explain VSAM advanced functions, extended format data sets, and their major features
• explain data stripping
• explain compression
• explain multivolume allocation options
• explain extended addressability
• explain system managed buffering
• explain partial space release
• explain space constraint relief

Data set reorganization, backup, and recovery

describe the need for data set backup

explain the advantages and disadvantages of REPRO

explain the a...

Prerequisites

You should complete:

• z/OS Facilities (ES15)
• z/OS Job Control Language and Utilities (ES07)or
• Fundamental System Skills in z/OS (ES10)
• or have equivalent experience

Audience

This is an intermediate course for individuals who manage data sets using IDCAMS and VSAM.