CREATE TABLE test (uint32 UInt32, n_uint32 Nullable(UInt32), lc LowCardinality(String)) ENGINE=File(Arrow) SETTINGS output_format_arrow_low_cardinality_as_dictionary=1 insert into test select number, number, toString(number % 10000) from numbers(10000000) SELECT uint32 from test format Null SELECT n_uint32 from test format Null SELECT lc from test format Null DROP TABLE IF EXISTS test