1 20G CREATE TABLE optimized_select_final (d Date, key UInt64, value String) ENGINE = ReplacingMergeTree() PARTITION BY toYYYYMM(d) ORDER BY key INSERT INTO optimized_select_final SELECT toDate('2000-01-01'), 2*number, randomPrintableASCII(1000) FROM numbers(1000000) INSERT INTO optimized_select_final SELECT toDate('2020-01-01'), 2*number+1, randomPrintableASCII(1000) FROM numbers(1000000) SELECT * FROM optimized_select_final FINAL FORMAT Null SETTINGS max_threads = 8 SELECT * FROM optimized_select_final FINAL WHERE key % 10 = 0 FORMAT Null DROP TABLE IF EXISTS optimized_select_final