**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.
constexpr static auto DETACHED_DIR_NAME = "detached";
    
    struct DataPartStateAndInfo
    {
        DataPartState state;
        const MergeTreePartInfo & info;
    };
    
    struct DataPartStateAndPartitionID
    {
        DataPartState state;
        String partition_id;
    };
    STRONG_TYPEDEF(String, PartitionID)
    
    
    
    
    
    struct AlterConversions
    {
        
        std::unordered_map<String, String> rename_map;
        bool isColumnRenamed(const String & new_name) const { return rename_map.count(new_name) > 0; }
        String getColumnOldName(const String & new_name) const { return rename_map.at(new_name); }
    };
    struct LessDataPart
    {
        using is_transparent = void;
        bool operator()(const DataPartPtr & lhs, const MergeTreePartInfo & rhs) const { return lhs->info < rhs; }