# 1. Create a table and insert 10M rows distributed across 100 partitions

CREATE TABLE test2
(
    `p` UInt32,
    `val` String
)
ENGINE = MergeTree
PARTITION BY p
ORDER BY tuple()

INSERT INTO test2 SELECT
    number % 100 AS p,
    toString(rand() % 100) AS val
FROM numbers(10000000)

# 2. Simple select works and scans all 100 partitions and 10M rows as expected

SELECT count()
FROM test2
WHERE val = 'qwe'

┌─count()─┐
│       0 │
└─────────┘

1 rows in set. Elapsed: 0.072 sec. Processed 10.00 million rows, 109.00 MB (138.06 million rows/s., 1.50 GB/s.)

# 3. Add bloom filter

ALTER TABLE test2
    ADD INDEX idx_bloom val TYPE bloom_filter GRANULARITY 1

# 4. Repeat the query

SELECT count()
FROM test2
WHERE val = 'qwe'

Query id: 4f5dbf5f-5c0d-441f-b6c9-1a9d3261658e


0 rows in set. Elapsed: 0.005 sec. 

Received exception from server (version 21.10.2):
Code: 1001. DB::Exception: Received from clickhouse-server:9000. DB::Exception: std::__1::__fs::filesystem::filesystem_error: filesystem error: in file_size:
No such file or directory [/var/lib/clickhouse/store/303/303e3f5f-9f67-4ac6-b03e-3f5f9f674ac6/0_1_576_1/skp_idx_idx_bloom.mrk3]. (STD_EXCEPTION)

# 5. If index is materialized with "ALTER TABLE test2 MATERIALIZE INDEX idx_bloom" eveything is back to normal