VSAM KSDS File Status Handling in COBOL Batch Support: Reads, Updates, and Recovery Checks
Learn practical VSAM KSDS file status handling in COBOL batch support, including reads, updates, recovery checks, and support-friendly diagnostics.
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Original tutorials and notes written for mainframe learners and production-support developers.
JCL Restart Strategy for Batch Support: Safe PROCSTEP Restarts, GDG Handling, and Return Codes
Learn a safe JCL restart approach for production batch support, including PROCSTEP restarts, GDG handling, return codes, and restart checklists.
COBOL File Handling Basics: Sequential Files, File Status, and Practical Flow
Learn how COBOL file handling works with SELECT, FD, OPEN, READ, WRITE, CLOSE, and file status checks.
JCL JOB, EXEC, and DD Statements Explained for Beginners
Understand the three core JCL statements used in almost every mainframe batch job: JOB, EXEC, and DD.
JCL Return Codes and Conditional Execution: How Batch Flow is Controlled
Learn how JCL return codes control step execution using COND, IF/THEN/ELSE, and production-safe patterns.
GDG Basics in JCL: Generation Data Groups Explained with Examples
Understand GDG datasets, relative generations, and common JCL usage patterns for daily batch processing.
Purpose: This site is maintained by Balasubramanian Duraiswamy to share practical mainframe learning notes and modernization ideas based on enterprise development and support experience.