TRUNCATE TABLE [IF EXISTS] [db.]name [ON CLUSTER cluster]
Removes all data from a table. When the clause
IF EXISTS is omitted, the query returns an error if the table does not exist.
TRUNCATE query is not supported for View, File, URL, Buffer and Null table engines.
You can use the alter_sync setting to set up waiting for actions to be executed on replicas.
You can specify how long (in seconds) to wait for inactive replicas to execute
TRUNCATE queries with the replication_wait_for_inactive_replica_timeout setting.
alter_sync is set to
2 and some replicas are not active for more than the time, specified by the
replication_wait_for_inactive_replica_timeout setting, then an exception
UNFINISHED is thrown.