SET send_logs_level = 'none'; SET joined_subquery_requires_alias = 0; DROP TABLE IF EXISTS delta_codec_synthetic; DROP TABLE IF EXISTS default_codec_synthetic; CREATE TABLE delta_codec_synthetic ( id UInt64 Codec(Delta, ZSTD(3)) ) ENGINE MergeTree() ORDER BY tuple(); CREATE TABLE default_codec_synthetic ( id UInt64 Codec(ZSTD(3)) ) ENGINE MergeTree() ORDER BY tuple(); INSERT INTO delta_codec_synthetic SELECT number FROM system.numbers LIMIT 5000000; INSERT INTO default_codec_synthetic SELECT number FROM system.numbers LIMIT 5000000; OPTIMIZE TABLE delta_codec_synthetic FINAL; OPTIMIZE TABLE default_codec_synthetic FINAL; SELECT floor(big_size / small_size) AS ratio FROM (SELECT 1 AS key, sum(bytes_on_disk) AS small_size FROM system.parts WHERE database == currentDatabase() and table == 'delta_codec_synthetic') INNER JOIN (SELECT 1 AS key, sum(bytes_on_disk) as big_size FROM system.parts WHERE database == currentDatabase() and table == 'default_codec_synthetic') USING(key); SELECT small_hash == big_hash FROM (SELECT 1 AS key, sum(cityHash64(*)) AS small_hash FROM delta_codec_synthetic) INNER JOIN (SELECT 1 AS key, sum(cityHash64(*)) AS big_hash FROM default_codec_synthetic) USING(key); DROP TABLE IF EXISTS delta_codec_synthetic; DROP TABLE IF EXISTS default_codec_synthetic; DROP TABLE IF EXISTS delta_codec_float; DROP TABLE IF EXISTS default_codec_float; CREATE TABLE delta_codec_float ( id Float64 Codec(Delta, LZ4HC) ) ENGINE MergeTree() ORDER BY tuple(); CREATE TABLE default_codec_float ( id Float64 Codec(LZ4HC) ) ENGINE MergeTree() ORDER BY tuple(); INSERT INTO delta_codec_float SELECT number FROM numbers(1547510400, 500000) WHERE number % 3 == 0 OR number % 5 == 0 OR number % 7 == 0 OR number % 11 == 0; INSERT INTO default_codec_float SELECT * from delta_codec_float; OPTIMIZE TABLE delta_codec_float FINAL; OPTIMIZE TABLE default_codec_float FINAL; SELECT floor(big_size / small_size) as ratio FROM (SELECT 1 AS key, sum(bytes_on_disk) AS small_size FROM system.parts WHERE database = currentDatabase() and table = 'delta_codec_float') INNER JOIN (SELECT 1 AS key, sum(bytes_on_disk) as big_size FROM system.parts WHERE database = currentDatabase() and table = 'default_codec_float') USING(key); SELECT small_hash == big_hash FROM (SELECT 1 AS key, sum(cityHash64(*)) AS small_hash FROM delta_codec_float) INNER JOIN (SELECT 1 AS key, sum(cityHash64(*)) AS big_hash FROM default_codec_float) USING(key); DROP TABLE IF EXISTS delta_codec_float; DROP TABLE IF EXISTS default_codec_float; DROP TABLE IF EXISTS delta_codec_string; DROP TABLE IF EXISTS default_codec_string; CREATE TABLE delta_codec_string ( id Float64 Codec(Delta, LZ4) ) ENGINE MergeTree() ORDER BY tuple(); CREATE TABLE default_codec_string ( id Float64 Codec(LZ4) ) ENGINE MergeTree() ORDER BY tuple(); INSERT INTO delta_codec_string SELECT concat(toString(number), toString(number % 100)) FROM numbers(1547510400, 500000); INSERT INTO default_codec_string SELECT * from delta_codec_string; OPTIMIZE TABLE delta_codec_string FINAL; OPTIMIZE TABLE default_codec_string FINAL; SELECT floor(big_size / small_size) as ratio FROM (SELECT 1 AS key, sum(bytes_on_disk) AS small_size FROM system.parts WHERE database = currentDatabase() and table = 'delta_codec_string') INNER JOIN (SELECT 1 AS key, sum(bytes_on_disk) as big_size FROM system.parts WHERE database = currentDatabase() and table = 'default_codec_string') USING(key); SELECT small_hash == big_hash FROM (SELECT 1 AS key, sum(cityHash64(*)) AS small_hash FROM delta_codec_string) INNER JOIN (SELECT 1 AS key, sum(cityHash64(*)) AS big_hash FROM default_codec_string) USING(key); DROP TABLE IF EXISTS delta_codec_string; DROP TABLE IF EXISTS default_codec_string;