**How to reproduce**
Clickhouse server 20.13.1.5273
```
CREATE TABLE default.test
(
`key` UInt32,
`ts` DateTime CODEC(DoubleDelta, LZ4),
`db_time` DateTime DEFAULT now() COMMENT 'spout-ignore' CODEC(DoubleDelta, LZ4)
)
ENGINE = MergeTree
PARTITION BY toStartOfTenMinutes(db_time)
ORDER BY (key, ts)
TTL db_time + toIntervalHour(3)
SETTINGS index_granularity = 8192, merge_with_ttl_timeout = 3600, min_rows_for_compact_part = 1000000, min_bytes_for_compact_part = 200000000, in_memory_parts_enable_wal = 0;


INSERT INTO test(key, ts) SELECT number % 1000, now() + intDiv(number,1000) FROM numbers(500);

SELECT * FROM test;
500 rows in set. Elapsed: 0.003 sec.

DETACH TABLE test;

ATTACH TABLE test;

SELECT * FROM test;

0 rows in set. Elapsed: 0.002 sec.
```

**Expected behavior**
Clickhouse would flush parts on disk.
{
    total_active_size_bytes.store(bytes, std::memory_order_release);
    total_active_size_rows.store(rows, std::memory_order_release);
    total_active_size_parts.store(parts, std::memory_order_release);
}
bool MergeTreeData::insertQueryIdOrThrow(const String & query_id, size_t max_queries) const
{
    std::lock_guard lock(query_id_set_mutex);
    return insertQueryIdOrThrowNoLock(query_id, max_queries, lock);
}
bool MergeTreeData::insertQueryIdOrThrowNoLock(const String & query_id, size_t max_queries, const std::lock_guard<std::mutex> &) const
{
    if (query_id_set.find(query_id) != query_id_set.end())
        return false;
    if (query_id_set.size() >= max_queries)
        throw Exception(
            ErrorCodes::TOO_MANY_SIMULTANEOUS_QUERIES, "Too many simultaneous queries for table {}. Maximum is: {}", log_name, max_queries);
    query_id_set.insert(query_id);
    return true;
}
void MergeTreeData::removeQueryId(const String & query_id) const
{
    std::lock_guard lock(query_id_set_mutex);
    removeQueryIdNoLock(query_id, lock);
}
void MergeTreeData::removeQueryIdNoLock(const String & query_id, const std::lock_guard<std::mutex> &) const