**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.
}
            catch (const fs::filesystem_error & e)
            {
                if (e.code() == std::errc::no_such_file_or_directory)
                {
                    
                }
                else
                    throw;
            }
        }
    }
    return cleared_count;
}
MergeTreeData::DataPartsVector MergeTreeData::grabOldParts(bool force)
{
    DataPartsVector res;
    
    std::unique_lock lock(grab_old_parts_mutex, std::defer_lock);
    if (!lock.try_lock())
        return res;
    time_t now = time(nullptr);
    std::vector<DataPartIteratorByStateAndInfo> parts_to_delete;
    {
        auto parts_lock = lockParts();
        auto outdated_parts_range = getDataPartsStateRange(DataPartState::Outdated);
        for (auto it = outdated_parts_range.begin(); it != outdated_parts_range.end(); ++it)
        {
            const DataPartPtr & part = *it;
            auto part_remove_time = part->remove_time.load(std::memory_order_relaxed);