**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.
{
                    for (const auto & [_, projection_part] : part->getProjectionParts())
                        res.push_back(projection_part);
                }
            }
            else
            {
                std::swap(buf, res);
                res.clear();
                std::merge(range.begin(), range.end(), buf.begin(), buf.end(), std::back_inserter(res), LessDataPart()); /
            }
        }
        if (out_states != nullptr)
        {
            out_states->resize(res.size());
            if (require_projection_parts)
            {
                for (size_t i = 0; i < res.size(); ++i)
                    (*out_states)[i] = res[i]->getParentPart()->getState();
            }
            else
            {
                for (size_t i = 0; i < res.size(); ++i)
                    (*out_states)[i] = res[i]->getState();
            }
        }
    }
    return res;
}
MergeTreeData::DataPartsVector