Learn RPG with Real Code Examples
Updated Nov 20, 2025
Architecture
Procedural language focused on file and record operations
Batch and interactive execution supported
Integration with DB2 database for data access
Modular subprocedures for reuse
Report-oriented I/O for business applications
Rendering Model
Source code compiled by IBM i compiler
Program executes record by record
Calculations and logic applied to each record
Reports formatted for output files
Optional interactive display for user input
Architectural Patterns
Procedural and modular subprocedure-based design
File I/O driven workflow
Batch processing and scheduling
Integration with DB2 database
Report-centric application structure
Real World Architectures
Payroll processing systems
Inventory management systems
Financial reporting applications
Customer billing and order processing
ERP modules on IBM i
Design Principles
Optimized for business reports and calculations
File-centric and record-oriented
Procedural with optional modularization
Batch and interactive execution support
Integration with DB2 and IBM i features
Scalability Guide
Modularize large programs into subprocedures
Organize libraries for reusable code
Optimize batch job performance
Use indexes for DB2 queries
Implement error handling and logging
Migration Guide
Transition fixed-format RPG to free-format RPG IV
Refactor calculations into subprocedures
Update file access for modern DB2 tables
Leverage APIs for GUI or web integration
Maintain backward compatibility for legacy jobs