DROP TABLE IF EXISTS test.alter; CREATE TABLE test.alter (d Date, k UInt64, i32 Int32) ENGINE=MergeTree(d, k, 8192); INSERT INTO test.alter VALUES ('2015-01-01', 10, 42); DESC TABLE test.alter; SHOW CREATE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; ALTER TABLE test.alter ADD COLUMN n Nested(ui8 UInt8, s String); INSERT INTO test.alter VALUES ('2015-01-01', 8, 40, [1,2,3], ['12','13','14']); DESC TABLE test.alter; SHOW CREATE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; ALTER TABLE test.alter ADD COLUMN `n.d` Array(Date); INSERT INTO test.alter VALUES ('2015-01-01', 7, 39, [10,20,30], ['120','130','140'],['2000-01-01','2000-01-01','2000-01-03']); DESC TABLE test.alter; SHOW CREATE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; ALTER TABLE test.alter ADD COLUMN s String DEFAULT '0'; INSERT INTO test.alter VALUES ('2015-01-01', 6,38,[10,20,30],['asd','qwe','qwe'],['2000-01-01','2000-01-01','2000-01-03'],'100500'); DESC TABLE test.alter; SHOW CREATE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; ALTER TABLE test.alter DROP COLUMN `n.d`, MODIFY COLUMN s Int64; DESC TABLE test.alter; SHOW CREATE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; ALTER TABLE test.alter ADD COLUMN `n.d` Array(Date), MODIFY COLUMN s UInt32; DESC TABLE test.alter; SHOW CREATE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; OPTIMIZE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; ALTER TABLE test.alter DROP COLUMN n.ui8, DROP COLUMN n.d; DESC TABLE test.alter; SHOW CREATE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; ALTER TABLE test.alter DROP COLUMN n.s; DESC TABLE test.alter; SHOW CREATE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; ALTER TABLE test.alter ADD COLUMN n.s Array(String), ADD COLUMN n.d Array(Date); DESC TABLE test.alter; SHOW CREATE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; ALTER TABLE test.alter DROP COLUMN n; DESC TABLE test.alter; SHOW CREATE TABLE test.alter; SELECT * FROM test.alter ORDER BY k; DROP TABLE test.alter;