A comprehensive guide to DB2 for i JSON and XML functions in 2026: extracting scalars with JSON_VALUE, shredding arrays with JSON_TABLE, constructing responses with JSON_OBJECT and JSON_ARRAYAGG, producing JSON with FOR JSON, parsing XML with XMLTABLE, and building a complete REST payload processor stored procedure.
A deep dive into the IBM i ILE binding model: how modules, programs, service programs, and binding directories relate, how CRTPGM and CRTSRVPGM work, the difference between *NEW, *CALLER, and named activation groups, and how to design reusable service programs for production IBM i systems in 2026.
Master IBM i CL exception handling in 2026: message file architecture, CRTMSGF and ADDMSGD to define messages, SNDPGMMSG for escape and informational messages, MONMSG for structured exception catching, RCVMSG to retrieve message data, and a complete CL error handling programme template with DB2 audit logging.
A practical guide to IBM i security hardening in 2026: QSECURITY levels 10–50, auditing user profiles with QSYS2.USER_INFO, removing excessive special authorities, object authority management, enabling QAUDJRN, hardening network services, and applying Row and Column Access Control in DB2 for i.
A comprehensive guide to DB2 for i SQL stored procedures and user-defined functions in 2026: CREATE PROCEDURE syntax, IN/OUT parameters, cursor loops, calling from RPG and Node.js, scalar and table UDFs, and external stored procedures backed by ILE RPG programs.
A practical guide to using AI and large language models to document legacy IBM i RPG programs in 2026: extracting source code from IBM i, calling GPT-4o and IBM Granite via API, prompt engineering for RPG documentation, building a batch documentation pipeline, and creating a semantic search knowledge base over your entire IBM i codebase.
A complete guide to IBM i system startup and shutdown procedures in 2026: understanding the IPL sequence, configuring QSTRUP, starting TCP/IP and subsystems with STRTCP and STRSBS, performing controlled shutdowns with ENDSBS and PWRDWNSYS, scheduling maintenance IPLs, and diagnosing common startup failures.
HTTPAPI by Scott Klement is the standard open source library for making outbound HTTP calls from IBM i RPG programs. This post covers installing HTTPAPI and YAJL, making GET and POST requests, parsing JSON responses, implementing the OAuth 2.0 client credentials flow from ILE RPG, and managing SSL certificates on IBM i.
DB2 for i triggers fire automatically on INSERT, UPDATE, and DELETE, enforcing rules that application code cannot bypass. This post covers SQL and external trigger types, BEFORE and AFTER timing, transition variables, writing audit tables, calling RPG programs from external triggers using ADDPFTRG, and practical audit and validation patterns.
A complete guide to RPGUnit for ILE RPG in 2026: install the framework, write test cases and test suites for RPG service programs, run tests with RURUN, parse TAP output, and integrate automated RPG testing into a Bob or Jenkins CI pipeline.