ClickHouse/tests/integration/test_materialized_mysql_database/configs/users.xml

<clickhouse>
    <profiles>
        <default>
            <allow_experimental_database_materialized_mysql>1</allow_experimental_database_materialized_mysql>
            <allow_introspection_functions>1</allow_introspection_functions>
            <optimize_on_insert>0</optimize_on_insert>
        </default>
    </profiles>

    <users>
        <default>
            <password></password>
            <networks incl="networks" replace="replace">
                <ip>::/0</ip>
            </networks>
            <profile>default</profile>
            <named_collection_control>1</named_collection_control>
        </default>
    </users>
</clickhouse>