versionchange

Versionchange is a term used to describe a mechanism for encoding and applying changes required to upgrade from one version of a system, schema, or data format to another. It encompasses the set of transformations, compatibility checks, and validation steps that accompany a version upgrade.

In software development and data management, versionchange is used in release engineering, database migrations, API evolution, and configuration management to minimize disruption by isolating changes into discrete steps.

A versionchange specification typically includes identifiers for the source and target versions, a list of operations (such as field renaming, type conversion, or default value reassignment), and rules for how to apply and verify the migration. Implementations may run at deployment time, in a migration tool, or as part of a runtime upgrade path.

Example: A JSON-based configuration format uses a versionchange delta to rename a field, convert a numeric value to a string, and populate a new optional field with a default. The system applies the delta when loading a configuration with an older version, then stores it as the new version.

Challenges: versionchange requires careful ordering of operations, data integrity guarantees, and rollback strategies. Poorly designed migrations can cause data loss or downtime. It is closely related to semantic versioning, database migrations, and data transformation pipelines.