Allow Parallel Execution of Distributed DDL in ClickHouse

Why it matters

This feature improves the efficiency and reduces the execution time of distributed DDL commands by enabling them to run in parallel across the cluster. It solves the problem of sequential execution delays when applying DDL statements to distributed tables and nodes, which is especially beneficial in large-scale deployments.

How to use it

Distributed DDL commands are executed in parallel by default when issued on distributed tables. Users simply need to run their DDL statements (such as ALTER TABLE, CREATE TABLE, or DROP TABLE) on distributed tables without additional configuration to take advantage of parallel execution.