ClickHouse/tests/queries/0_stateless/02675_sparse_columns_clear_column.sql

DROP TABLE IF EXISTS t_sparse_columns_clear;

CREATE TABLE t_sparse_columns_clear (arr Array(UInt64), v UInt64)
ENGINE = MergeTree ORDER BY tuple()
SETTINGS
    ratio_of_defaults_for_sparse_serialization = 0.9,
    min_bytes_for_wide_part=0;

INSERT INTO t_sparse_columns_clear SELECT [number], 0 FROM numbers(1000);

SELECT column, serialization_kind FROM system.parts_columns
WHERE database = currentDatabase() AND table = 't_sparse_columns_clear' AND active
ORDER BY column;

SET mutations_sync = 2;
SET alter_sync = 2;

ALTER TABLE t_sparse_columns_clear CLEAR COLUMN v;

SELECT column, serialization_kind FROM system.parts_columns
WHERE database = currentDatabase() AND table = 't_sparse_columns_clear' AND active
ORDER BY column;

OPTIMIZE TABLE t_sparse_columns_clear FINAL;

SELECT column, serialization_kind FROM system.parts_columns
WHERE database = currentDatabase() AND table = 't_sparse_columns_clear' AND active
ORDER BY column;

DROP TABLE t_sparse_columns_clear SYNC;

SYSTEM FLUSH LOGS;
SET max_rows_to_read = 0; -- system.text_log can be really big
SELECT count(), groupArray(message) FROM system.text_log WHERE logger_name LIKE '%' || currentDatabase() || '.t_sparse_columns_clear' || '%' AND level = 'Error';