Introduces versioning support for aggregate function states, enabling backward-compatible changes in the serialization format of aggregate function states in ClickHouse.
Why it matters
This feature addresses the problem of incompatibility when changing the serialization format of aggregate function states. By allowing versioning, ClickHouse can introduce improvements or fixes to aggregate function state serialization without breaking existing data or queries, thus ensuring smoother upgrades and better stability.How to use it
This feature is utilized internally by ClickHouse when serializing and deserializing aggregate function states. Users benefit automatically from backward compatibility when upgrading ClickHouse. No explicit user action is required to enable this feature.