After completing this course, the student should be able to:
 

	Describe the features of VSAM
	Define key terms in VSAM
	Compare and contrast the characteristics of the main types of VSAM data sets
	Explain the internal structure of VSAM data sets
	Describe VSAM data set processing
	Explain how an alternate index is used

VSAM Overview
Deals with some of the features of VSAM as well as with some of the advantages and disadvantages to using VSAM.  Presents terminology associated with VSAM.
 

	Features and Benefits Features of VSAM.  Advantages and disadvantages of VSAM.
	Terminology: Storing Key terms in VSAM: ESDS, RRDS, KSDS, cluster, data component, index component, records, CIs, CAs, sequence set and index set.
	Terminology: Accessing/Cataloging Key terms in VSAM: sequential access, direct access, access via an alternate index, ICF catalogs and VSAM catalogs, master catalogs and user catalogs.

VSAM Data Set Structure
Examines the internal structure of VSAM data sets.
 

	Records, CIs, CAs Basics about records, control intervals and control areas.
	Data CI Structure Internal structure of a data control interval.  Record definition fields and control interval definition fields.  Spanned records.
	KSDS Structure Internal structure of a key-sequenced data set.

VSAM Data Set Processing
Describes how VSAM inserts and deletes records in the data component of a KSDS.  Examines ESDS and RRDS VSAM processing and looks at temporary VSAM data sets.
 

	KSDS Updates KSDS processing when VSAM inserts a record in a CI containing enough free space.
	KSDS Updates: With CI/CA Splits Why and how control interval and control area splits occur.
	KSDS Insertion Techniques Normal insertion strategy versus sequential insertion strategy.
	Other Data Set Types Record organization in ESDSs and RRDSs.  How records are added, deleted and accessed for each.  Function of a VSAM temporary data set.

VSAM Alternate Indexes
Examines the alternate index, one of two types of index within VSAM.
 

	Concepts A prime index versus an alternate index.  How an alternate index is used.  Differences between unique and non-unique keys.
	Processing and Accessing What an upgradable alternate index is.  How VSAM maintains one.  Function of a path.

VSAM Data Set Indexes
Provides detailed information about the index component of a VSAM data set.  
 

	Key Compression Purpose of key compression.  How key compression works.
	Index Record Format Format of an index record from the index set and from the sequence set.