Add Experimental Replicated Database Engine with DDL Query Replication

Why it matters

This feature addresses the need for synchronizing DDL operations, ensuring that schema changes are consistently applied across all replicas in a distributed ClickHouse environment, improving cluster management and reducing manual synchronization errors.

How to use it

To use the Replicated database engine, create a database with the engine specified as Replicated. This will enable automatic replication of DDL queries among the hosts configured in the cluster.