DROP TABLE IF EXISTS test.alter; CREATE TABLE test.alter (d Date, x UInt8) ENGINE = ReplicatedMergeTree('/clickhouse/tables/test/alter', 'r1', d, (d), 8192); INSERT INTO test.alter VALUES ('2014-01-01', 1); ALTER TABLE test.alter DROP COLUMN x; SELECT value FROM system.zookeeper WHERE path = '/clickhouse/tables/test/alter/replicas/r1/parts/20140101_20140101_200_200_0' AND name = 'columns' FORMAT TabSeparatedRaw; DROP TABLE test.alter; CREATE TABLE test.alter (d Date) ENGINE = ReplicatedMergeTree('/clickhouse/tables/test/alter', 'r1', d, (d), 8192); INSERT INTO test.alter VALUES ('2014-01-01'); SELECT * FROM test.alter ORDER BY d; ALTER TABLE test.alter ADD COLUMN x UInt8; INSERT INTO test.alter VALUES ('2014-02-01', 1); SELECT * FROM test.alter ORDER BY d; ALTER TABLE test.alter DROP COLUMN x; SELECT * FROM test.alter ORDER BY d; SELECT value FROM system.zookeeper WHERE path = '/clickhouse/tables/test/alter/replicas/r1/parts/20140201_20140201_200_200_0' AND name = 'columns' FORMAT TabSeparatedRaw; DROP TABLE test.alter;