design_patterns-horizontal_versioning

Persistent data schema versioning maintains backward compatibility by creating separate structs for each version, implementing explicit Upgrade() methods for forward migrations, and using type-string registered coders to deserialize old data into the correct concrete version.

The best way to implement a data migration upgrade path is defining explicit Upgrade() methods on previous version structs, enabling forward-compatible migrations to the next version without losing deserialized data fidelity.

The CoderToTypedBlob pattern handles type-safe serialization by registering explicit type strings and coders in a coder map, ensuring persistent versioned data deserializes into the correct concrete version struct during storage retrieval.

Yes, horizontal versioning applies to blob types and coder registrations by isolating version implementations into separate structs, allowing old data deserialization through registered type strings while supporting forward upgrades.

Using separate structs for each version provides isolated version implementations and explicit upgrade paths, preventing breaking changes to persistent data structures while ensuring safe forward migrations and type-safe deserialization.