v.1.1.54245New Features

Distributed DDL

Official CH changelog text
Distributed DDL (for example, CREATE TABLE ON CLUSTER)
Introduces support for Distributed DDL statements such as CREATE TABLE ON CLUSTER in ClickHouse, enabling the execution of DDL commands across all nodes in a cluster automatically.

Why it matters

This feature was created to simplify and automate schema changes in a distributed ClickHouse setup. Previously, users had to execute DDL queries individually on each node, which was error-prone and cumbersome. By enabling Distributed DDL, users can ensure consistent schema changes across all replicas and shards easily, thus improving cluster management, reducing manual work, and preventing synchronization issues.

How to use it

Use the syntax CREATE TABLE your_table ON CLUSTER cluster_name (...) to create a table on all nodes in the specified cluster simultaneously. This requires defining the cluster configuration in ClickHouse server settings. The DDL query is sent to the distributed_ddl system table and asynchronously executed on all nodes included in the cluster.

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