Further Reading — Chapter 11: Sequential File Processing

Official Documentation

  • IBM Enterprise COBOL for z/OS: Language Reference — FILE-CONTROL paragraph, FD entry, READ statement, WRITE statement. The definitive syntax reference for sequential file I/O.

  • Available at: IBM Documentation (online), SC27-1408

  • IBM Enterprise COBOL for z/OS: Programming Guide — "Processing sequential files" chapter. Covers practical aspects including blocking, buffering, and performance optimization.

  • Available at: IBM Documentation (online), SC27-1412

  • IBM z/OS DFSMS: Using Data Sets — Comprehensive guide to z/OS dataset management including sequential datasets, PDSs, VSAM, and GDGs.

  • Available at: IBM Documentation (online), SC23-6855

  • GnuCOBOL Programmer's Guide — Sequential and line-sequential file handling. Covers GnuCOBOL-specific behavior and the differences from z/OS.

Books

  • Stern, Stern, & Ley, "COBOL for the 21st Century" — Chapters on sequential file processing with progressive examples from simple reads through multi-file processing.

  • Sayles, "Advanced COBOL for Structured and Object-Oriented Programming" — Advanced sequential file techniques including variable-length records, multiple record types, and performance optimization.

  • Lowe, "JCL: Job Control Language" — Essential companion for understanding how JCL DD statements connect to COBOL SELECT statements and how DCB parameters affect file behavior.

Articles and Technical References

  • "z/OS Sequential File Processing Performance" — IBM technical note on optimizing blocking factors, buffer allocation, and I/O scheduling for sequential datasets.

  • "The Balanced Line Algorithm" — Classic algorithm description for merging and match-updating sorted sequential files. Foundational for understanding batch COBOL processing patterns.

  • "Generation Data Groups (GDG) Best Practices" — IBM Redbook chapter on managing sequential file generations for archival and audit purposes.

  • "COBOL Sequential File Processing Patterns" — Survey of common patterns including copy, filter, split, merge, match-update, and control break.

Tools

  • IBM DFSORT (ICETOOL) — z/OS utility for sorting, merging, copying, and reformatting sequential files. Often used in JCL steps before or after COBOL programs.

  • IBM File Manager for z/OS — Utility for browsing, editing, and comparing sequential files using COBOL copybook layouts.

  • IBM Batch Toolkit for z/OS — Utilities for managing batch job flows, checkpoint/restart, and sequential file operations.

  • GnuCOBOL — Free COBOL compiler for Linux/Mac/Windows. Excellent for practicing sequential file processing in the Student Lab environment.

  • Chapter 10: Defensive Programming — FILE STATUS checking patterns used throughout this chapter
  • Chapter 12: Indexed File Processing — VSAM KSDS files for random access (contrasts with sequential)
  • Chapter 13: Relative File Processing — Relative record number access
  • Chapter 14: Control Break Processing — Multi-level reporting from sorted sequential files
  • Chapter 15: SORT and MERGE — COBOL's built-in facility for sorting and merging sequential files
  • Chapter 16: Report Writer — COBOL's declarative report generation facility