DROP TABLE IF EXISTS mutation_table;

CREATE TABLE mutation_table
(
    date Date,
    key UInt64,
    value String
)
ENGINE = MergeTree()
PARTITION BY date
ORDER BY tuple();

INSERT INTO mutation_table SELECT toDate('2019-10-01'), number, '42' FROM numbers(100);

INSERT INTO mutation_table SELECT toDate('2019-10-02'), number, 'Hello' FROM numbers(100);

SELECT distinct(value) FROM mutation_table ORDER BY value;

ALTER TABLE mutation_table MODIFY COLUMN value UInt64 SETTINGS mutations_sync = 2; --{serverError 341}

SELECT distinct(value) FROM mutation_table ORDER BY value; --{serverError 6}

KILL MUTATION where table = 'mutation_table' and database = currentDatabase();

ALTER TABLE mutation_table MODIFY COLUMN value String SETTINGS mutations_sync = 2;

SELECT distinct(value) FROM mutation_table ORDER BY value;

DROP TABLE IF EXISTS mutation_table;