distributed_ddl_* session settings

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distributed_ddl_entry_format_version

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distributed_ddl_output_mode

• throw — Returns result set with query execution status for all hosts where query is finished. If query has failed on some hosts, then it will rethrow the first exception. If query is not finished yet on some hosts and distributed_ddl_task_timeout exceeded, then it throws TIMEOUT_EXCEEDED exception.
• none — Is similar to throw, but distributed DDL query returns no result set.
• null_status_on_timeout — Returns NULL as execution status in some rows of result set instead of throwing TIMEOUT_EXCEEDED if query is not finished on the corresponding hosts.
• never_throw — Do not throw TIMEOUT_EXCEEDED and do not rethrow exceptions if query has failed on some hosts.
• none_only_active - similar to none, but doesn’t wait for inactive replicas of the Replicated database. Note: with this mode it’s impossible to figure out that the query was not executed on some replica and will be executed in background.
• null_status_on_timeout_only_active — similar to null_status_on_timeout, but doesn’t wait for inactive replicas of the Replicated database
• throw_only_active — similar to throw, but doesn’t wait for inactive replicas of the Replicated database

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distributed_ddl_task_timeout

• Positive integer.
• 0 — Async mode.
• Negative integer — infinite timeout.