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Languages & runtimes · #cobol
Learn how COBOL's EVALUATE statement replaces nested IFs with a clear, range‑capable multi‑way branch, illustrated by a status‑code‑to‑benefit example.
A practical COBOL pattern for reliable VSAM KSDS batch updates using explicit INVALID KEY handling and DECLARATIVES USE AFTER-ERROR, with checkpoint restart and error logging without abend.
Learn how COBOL programmers can add or subtract days safely with the standard intrinsic functions DATE-OF-INTEGER and INTEGER-OF-DATE, avoiding manual leap‑year logic.
Embedded SQL lets COBOL programs access DB2 directly, but you must design for trust boundaries, operational checks, and failure modes. This article outlines a minimal architecture, sample code, and when to consider redesigning.
Learn how COBOL’s COMP-3 packed decimal type provides exact base‑10 arithmetic for financial ledgers, with a worked example, pitfalls, and verification steps.
Before restoring a COBOL program from backup, it is necessary to confirm that the backup file is complete and has not been corrupted, while also ensuring that the source or object code remains usable in the target environment. Common approaches involve comparing checksums or hash values, verifying file‑size against the original backup, and attempting a compi
In a COBOL application running under CICS, maintaining data integrity during transaction retries is critical. While the use of sync-points and the EXEC CICS SYNCPOINT command ensures that a Logical Unit of Work (LUW) is processed atomically, the system does not natively track whether a specific business event has already been persisted if the transaction is
Migrating a legacy COBOL application to a modern schema without downtime requires a shadowing strategy where data is dual-written to both the legacy mainframe and a target system. A primary challenge involves the REDEFINES clause in the Data Division, which allows a single memory area to be interpreted as multiple distinct data structures. While sequential f
COBOL relies on a strict mapping between the FILE SECTION and the physical storage of a dataset. Because the record layout is defined by fixed-length PICTURE clauses, any modification to the data structure—such as inserting a new field or expanding an existing one—shifts the byte offsets for all subsequent fields in the record. When updating a schema to acco