ClickHouse/tests/queries/0_stateless/01780_column_sparse_alter.sql
2021-12-01 21:21:38 +03:00

27 lines
908 B
SQL

SET mutations_sync = 2;
DROP TABLE IF EXISTS t_sparse_alter;
CREATE TABLE t_sparse_alter (id UInt64, u UInt64, s String)
ENGINE = MergeTree ORDER BY id
SETTINGS ratio_of_defaults_for_sparse_serialization = 0.5;
INSERT INTO t_sparse_alter SELECT
number,
if (number % 11 = 0, number, 0),
if (number % 13 = 0, toString(number), '')
FROM numbers(2000);
SELECT column, serialization_kind FROM system.parts_columns WHERE database = currentDatabase() AND table = 't_sparse_alter' AND active ORDER BY name;
SELECT uniqExact(u), uniqExact(s) FROM t_sparse_alter;
ALTER TABLE t_sparse_alter DROP COLUMN s, RENAME COLUMN u TO t;
ALTER TABLE t_sparse_alter MODIFY COLUMN t UInt16;
SELECT column, serialization_kind FROM system.parts_columns WHERE database = currentDatabase() AND table = 't_sparse_alter' AND active ORDER BY name;
SELECT uniqExact(t) FROM t_sparse_alter;
DROP TABLE t_sparse_alter;