Ordinary - ClickHouse Documentation

The Ordinary database engine is the legacy database engine. It stores each table’s metadata in a separate file and has been superseded by Atomic.

Ordinary is deprecated. Do not use it for new databases.

Creating a database

Creating an Ordinary database requires enabling allow_deprecated_database_ordinary:

SET allow_deprecated_database_ordinary = 1;

CREATE DATABASE legacy
ENGINE = Ordinary;

Migration

Use Atomic for new databases. It is the default database engine in open-source ClickHouse and supports atomic metadata operations, including non-blocking DROP TABLE and RENAME TABLE.

See also

Last modified on September 10, 2026