CREATE TABLE lot_of_string_arrays_src (`id` UInt64, `col00` Array(String), `col01` Array(String), `col02` Array(String), `col03` Array(String), `col04` Array(String), `col05` Array(String), `col06` Array(String), `col07` Array(String), `col08` Array(String), `col09` Array(String), `col10` Array(String), `col11` Array(String), `col12` Array(String), `col13` Array(String), `col14` Array(String), `col15` Array(String), `col16` Array(String), `col17` Array(String), `col18` Array(String), `col19` Array(String), `col20` Array(String), `col21` Array(String), `col22` Array(String), `col23` Array(String), `col24` Array(String), `col25` Array(String), `col26` Array(String), `col27` Array(String), `col28` Array(String), `col29` Array(String), `col30` Array(String), `col31` Array(String), `col32` Array(String), `col33` Array(String), `col34` Array(String), `col35` Array(String), `col36` Array(String), `col37` Array(String), `col38` Array(String), `col39` Array(String), `col40` Array(String), `col41` Array(String), `col42` Array(String), `col43` Array(String), `col44` Array(String), `col45` Array(String), `col46` Array(String), `col47` Array(String), `col48` Array(String), `col49` Array(String)) ENGINE = MergeTree ORDER BY id SETTINGS index_granularity = 8192; CREATE TABLE lot_of_string_arrays_dst_lowcardinality (`id` UInt64, `col00` Array(LowCardinality(String)), `col01` Array(LowCardinality(String)), `col02` Array(LowCardinality(String)), `col03` Array(LowCardinality(String)), `col04` Array(LowCardinality(String)), `col05` Array(LowCardinality(String)), `col06` Array(LowCardinality(String)), `col07` Array(LowCardinality(String)), `col08` Array(LowCardinality(String)), `col09` Array(LowCardinality(String)), `col10` Array(LowCardinality(String)), `col11` Array(LowCardinality(String)), `col12` Array(LowCardinality(String)), `col13` Array(LowCardinality(String)), `col14` Array(LowCardinality(String)), `col15` Array(LowCardinality(String)), `col16` Array(LowCardinality(String)), `col17` Array(LowCardinality(String)), `col18` Array(LowCardinality(String)), `col19` Array(LowCardinality(String)), `col20` Array(LowCardinality(String)), `col21` Array(LowCardinality(String)), `col22` Array(LowCardinality(String)), `col23` Array(LowCardinality(String)), `col24` Array(LowCardinality(String)), `col25` Array(LowCardinality(String)), `col26` Array(LowCardinality(String)), `col27` Array(LowCardinality(String)), `col28` Array(LowCardinality(String)), `col29` Array(LowCardinality(String)), `col30` Array(LowCardinality(String)), `col31` Array(LowCardinality(String)), `col32` Array(LowCardinality(String)), `col33` Array(LowCardinality(String)), `col34` Array(LowCardinality(String)), `col35` Array(LowCardinality(String)), `col36` Array(LowCardinality(String)), `col37` Array(LowCardinality(String)), `col38` Array(LowCardinality(String)), `col39` Array(LowCardinality(String)), `col40` Array(LowCardinality(String)), `col41` Array(LowCardinality(String)), `col42` Array(LowCardinality(String)), `col43` Array(LowCardinality(String)), `col44` Array(LowCardinality(String)), `col45` Array(LowCardinality(String)), `col46` Array(LowCardinality(String)), `col47` Array(LowCardinality(String)), `col48` Array(LowCardinality(String)), `col49` Array(LowCardinality(String))) ENGINE = MergeTree ORDER BY id SETTINGS index_granularity = 8192; CREATE TABLE lot_of_string_arrays_dst (`id` UInt64, `col00` Array(String), `col01` Array(String), `col02` Array(String), `col03` Array(String), `col04` Array(String), `col05` Array(String), `col06` Array(String), `col07` Array(String), `col08` Array(String), `col09` Array(String), `col10` Array(String), `col11` Array(String), `col12` Array(String), `col13` Array(String), `col14` Array(String), `col15` Array(String), `col16` Array(String), `col17` Array(String), `col18` Array(String), `col19` Array(String), `col20` Array(String), `col21` Array(String), `col22` Array(String), `col23` Array(String), `col24` Array(String), `col25` Array(String), `col26` Array(String), `col27` Array(String), `col28` Array(String), `col29` Array(String), `col30` Array(String), `col31` Array(String), `col32` Array(String), `col33` Array(String), `col34` Array(String), `col35` Array(String), `col36` Array(String), `col37` Array(String), `col38` Array(String), `col39` Array(String), `col40` Array(String), `col41` Array(String), `col42` Array(String), `col43` Array(String), `col44` Array(String), `col45` Array(String), `col46` Array(String), `col47` Array(String), `col48` Array(String), `col49` Array(String)) ENGINE = MergeTree ORDER BY id SETTINGS index_granularity = 8192; INSERT INTO lot_of_string_arrays_src SELECT intDiv( rowid, 50 ) as id, anyIf(arr, rowid % 50 = 00) as col00, anyIf(arr, rowid % 50 = 01) as col01, anyIf(arr, rowid % 50 = 02) as col02, anyIf(arr, rowid % 50 = 03) as col03, anyIf(arr, rowid % 50 = 04) as col04, anyIf(arr, rowid % 50 = 05) as col05, anyIf(arr, rowid % 50 = 06) as col06, anyIf(arr, rowid % 50 = 07) as col07, anyIf(arr, rowid % 50 = 08) as col08, anyIf(arr, rowid % 50 = 09) as col09, anyIf(arr, rowid % 50 = 10) as col10, anyIf(arr, rowid % 50 = 11) as col11, anyIf(arr, rowid % 50 = 12) as col12, anyIf(arr, rowid % 50 = 13) as col13, anyIf(arr, rowid % 50 = 14) as col14, anyIf(arr, rowid % 50 = 15) as col15, anyIf(arr, rowid % 50 = 16) as col16, anyIf(arr, rowid % 50 = 17) as col17, anyIf(arr, rowid % 50 = 18) as col18, anyIf(arr, rowid % 50 = 19) as col19, anyIf(arr, rowid % 50 = 20) as col20, anyIf(arr, rowid % 50 = 21) as col21, anyIf(arr, rowid % 50 = 22) as col22, anyIf(arr, rowid % 50 = 23) as col23, anyIf(arr, rowid % 50 = 24) as col24, anyIf(arr, rowid % 50 = 25) as col25, anyIf(arr, rowid % 50 = 26) as col26, anyIf(arr, rowid % 50 = 27) as col27, anyIf(arr, rowid % 50 = 28) as col28, anyIf(arr, rowid % 50 = 29) as col29, anyIf(arr, rowid % 50 = 30) as col30, anyIf(arr, rowid % 50 = 31) as col31, anyIf(arr, rowid % 50 = 32) as col32, anyIf(arr, rowid % 50 = 33) as col33, anyIf(arr, rowid % 50 = 34) as col34, anyIf(arr, rowid % 50 = 35) as col35, anyIf(arr, rowid % 50 = 36) as col36, anyIf(arr, rowid % 50 = 37) as col37, anyIf(arr, rowid % 50 = 38) as col38, anyIf(arr, rowid % 50 = 39) as col39, anyIf(arr, rowid % 50 = 40) as col40, anyIf(arr, rowid % 50 = 41) as col41, anyIf(arr, rowid % 50 = 42) as col42, anyIf(arr, rowid % 50 = 43) as col43, anyIf(arr, rowid % 50 = 44) as col44, anyIf(arr, rowid % 50 = 45) as col45, anyIf(arr, rowid % 50 = 46) as col46, anyIf(arr, rowid % 50 = 47) as col47, anyIf(arr, rowid % 50 = 48) as col48, anyIf(arr, rowid % 50 = 49) as col49 FROM ( SELECT intDiv( number, 4 ) as rowid, groupArray( base64Encode( left( reinterpretAsString( rand64() ), 6) ) ) as arr FROM numbers(2000000) GROUP BY rowid ) GROUP BY id optimize table lot_of_string_arrays_src system stop merges INSERT INTO lot_of_string_arrays_dst SELECT rand64() as id, columns('^col') FROM lot_of_string_arrays_src INSERT INTO lot_of_string_arrays_dst_lowcardinality SELECT rand64() as id, columns('^col') FROM lot_of_string_arrays_src system start merges DROP TABLE IF EXISTS lot_of_string_arrays_src DROP TABLE IF EXISTS lot_of_string_arrays_dst DROP TABLE IF EXISTS lot_of_string_arrays_dst_lowcardinality