versionable

Versionable is a property of an artifact, resource, or dataset indicating that its state can exist in multiple distinguishable versions over time. A versionable item maintains a history of states, allowing retrieval of a specific past version, comparison between versions, and, when appropriate, reversion to an earlier state or creation of parallel histories.

Key features typically include a unique version identifier (such as a version number or timestamp), associated metadata (author, date, rationale), and the content changes for each version. Historical states are usually treated as immutable to preserve provenance, support auditability, and enable deterministic replay of changes.

Versionable data appear across domains. In software development, source code repositories track versions of files and builds. In content management, documents and pages maintain revision histories. Databases may model versioning through temporal tables or event logs. APIs and data contracts can be versioned to manage backward compatibility.

Implementation approaches vary. Version control systems (VCS) like Git provide distributed, append-only history. Event sourcing stores domain events as the source of truth. Append-only logs and periodic snapshots are common in distributed databases and streaming platforms.

Versioning strategies differ as well. Semantic versioning encodes compatibility in version numbers (major.minor.patch). Timestamp-based and content-based versioning offer alternative signals of change and compatibility.

Benefits of making items versionable include improved auditability, reproducibility, safer rolls back, and better collaboration. Challenges can include storage overhead, merging conflicts, performance implications, and governance of version lifecycles.