CREATE DATABASE IF NOT EXISTS test; DROP TABLE IF EXISTS test.pk_order; SET optimize_read_in_order = 1; CREATE TABLE test.pk_order(a UInt64, b UInt64, c UInt64, d UInt64) ENGINE=MergeTree() ORDER BY (a, b); INSERT INTO test.pk_order(a, b, c, d) VALUES (1, 1, 101, 1), (1, 2, 102, 1), (1, 3, 103, 1), (1, 4, 104, 1); INSERT INTO test.pk_order(a, b, c, d) VALUES (1, 5, 104, 1), (1, 6, 105, 1), (2, 1, 106, 2), (2, 1, 107, 2); INSERT INTO test.pk_order(a, b, c, d) VALUES (2, 2, 107, 2), (2, 3, 108, 2), (2, 4, 109, 2); SELECT b FROM test.pk_order ORDER BY a, b; SELECT a FROM test.pk_order ORDER BY a, b; SELECT a, b FROM test.pk_order ORDER BY a, b; SELECT a, b FROM test.pk_order ORDER BY a DESC, b; SELECT a, b FROM test.pk_order ORDER BY a, b DESC; SELECT a, b FROM test.pk_order ORDER BY a DESC, b DESC; SELECT a FROM test.pk_order ORDER BY a DESC; SELECT a, b, c FROM test.pk_order ORDER BY a, b, c; SELECT a, b, c FROM test.pk_order ORDER BY a DESC, b, c; SELECT a, b, c FROM test.pk_order ORDER BY a, b DESC, c; SELECT a, b, c FROM test.pk_order ORDER BY a, b, c DESC; SELECT a, b, c FROM test.pk_order ORDER BY a DESC, b DESC, c; SELECT a, b, c FROM test.pk_order ORDER BY a DESC, b, c DESC; SELECT a, b, c FROM test.pk_order ORDER BY a, b DESC, c DESC; SELECT a, b, c FROM test.pk_order ORDER BY a DESC, b DESC, c DESC; DROP TABLE IF EXISTS test.pk_order; CREATE TABLE pk_order (d DateTime, a Int32, b Int32) ENGINE = MergeTree ORDER BY (d, a) PARTITION BY toDate(d) SETTINGS index_granularity=1; INSERT INTO pk_order SELECT toDateTime('2019-05-05 00:00:00') + INTERVAL number % 10 DAY, number, intHash32(number) from numbers(100); set max_block_size = 1; -- Currently checking number of read rows while reading in pk order not working precise. TODO: fix it. -- SET max_rows_to_read = 10; SELECT d FROM pk_order ORDER BY d LIMIT 5; SELECT d, b FROM pk_order ORDER BY d, b LIMIT 5; SELECT d, a FROM pk_order ORDER BY d DESC, a DESC LIMIT 5; SELECT d, a FROM pk_order ORDER BY d DESC, -a LIMIT 5; SELECT d, a FROM pk_order ORDER BY d DESC, a DESC LIMIT 5; SELECT toStartOfHour(d) as d1 FROM pk_order ORDER BY d1 LIMIT 5; DROP TABLE pk_order; CREATE TABLE pk_order (a Int, b Int) ENGINE = MergeTree ORDER BY (a / b); INSERT INTO pk_order SELECT number % 10 + 1, number % 6 + 1 from numbers(100); SELECT * FROM pk_order ORDER BY (a / b), a LIMIT 5;