set extremes = '1';
DROP TABLE IF EXISTS HASH_TEST_INSERT;
DROP TABLE IF EXISTS HASH_MV;
CREATE TABLE HASH_TEST_INSERT (`STR_VAL` String) ENGINE = Null;
CREATE MATERIALIZED VIEW HASH_MV (`HASH_VAL` UInt64, `STR_VAL` LowCardinality(String)) ENGINE = ReplacingMergeTree ORDER BY HASH_VAL AS SELECT xxHash64(STR_VAL) AS HASH_VAL, toLowCardinality(STR_VAL) AS STR_VAL FROM HASH_TEST_INSERT;
INSERT INTO HASH_TEST_INSERT VALUES ('a');