DROP TABLE IF EXISTS test.alter; CREATE TABLE test.alter (d Date, k UInt64, i32 Int32, n Nested(ui8 UInt8, s String)) ENGINE=MergeTree(d, k, 8192); INSERT INTO test.alter VALUES ('2015-01-01', 3, 30, [1,2,3], ['1','12','123']); INSERT INTO test.alter VALUES ('2015-01-01', 2, 20, [1,2], ['1','12']); INSERT INTO test.alter VALUES ('2015-01-01', 1, 10, [1], ['1']); ALTER TABLE test.alter ADD COLUMN `n.i8` Array(Int8) AFTER i32; SELECT `n.i8`, `n.ui8`, `n.s` FROM test.alter ORDER BY k; SELECT `n.i8` FROM test.alter ORDER BY k; OPTIMIZE TABLE test.alter; SELECT `n.i8` FROM test.alter ORDER BY k; DROP TABLE IF EXISTS test.alter;