DROP TABLE IF EXISTS test; CREATE TABLE test(a Int, b Int) Engine=ReplacingMergeTree order by a SETTINGS index_granularity = 8192, index_granularity_bytes = '10Mi'; INSERT INTO test select number, number from numbers(5); INSERT INTO test select number, number from numbers(5,2); set max_threads =1; explain pipeline select * from test final; select * from test final; set max_threads =2; explain pipeline select * from test final; DROP TABLE test;