(a 3-day course)
The students will learn the different Virtual Storage Access Method (VSAM) data set organisations and how to define
them for optimum performance.
Making use of practical exercises the students will learn how to invoke IDCAMS services and how to code COBOL VSAM
related I/O statements.
The students will learn how to interpret LISTCAT outputs and to identify the necessary tuning actions.
System programmers, operation analysts and application developers.
You need a working knowledge of the OS/390 or z/OS environment.
- Course contents
- Basic I/O Concepts
- block, logical record
- sequential, indexed and direct data processing
- access methods
- DASD: track, cylinder, access time, ...
- Non-VSAM data set organizations and access methods
- PS, PDS, IS, DA, and PDSE
- BSAM, QSAM, BPAM, ISAM, and BDAM
- VSAM record formats
- fixed, variable, and spanned
- VSAM data set organizations
- ESDS, fixed-length RRDS, variable-length RRDS, KSDS, and LDS
- VSAM internal organization
- CI, CI control information, CA, CI split, CA split, free space, ...
- IDCAMS commands
- LISTCAT, DEFINE CLUSTER, REPRO, PRINT, DELETE, ALTER, VERIFY, EXAMINE, ...
- Defining a VSAM cluster
- Loading a VSAM cluster
- Interpreting the LISTCAT output
- Using COBOL to process ESDS, RRDS, KSDS, KSDS with alternate keys
- File status and VSAM codes
- Optimizing VSAM performance
- space allocation, CI and CA size, free space, index options (IMBED and REPLICATE), buffering, ...
- Alternate Indexes, Paths
- DEFINE AIX, DEFINE PATH, BLDINDEX commands
- Concurrent processing
- NSR, LSR and GSR buffering
- BLSR subsystem
- VSAM and SMS
- Theoretical and practical exercices
Datatrain Course VSAM Utilities