**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.
throw Exception(ErrorCodes::BAD_ARGUMENTS,
                "Cannot drop or clear column{} '{}', because all columns in part '{}' will be removed from disk. Empty parts are not allowed", postfix, boost::algorithm::join(dropped_columns, ", "), part->name);
        }
    }
}
void MergeTreeData::checkMutationIsPossible(const MutationCommands & , const Settings & ) const
{
    
}
MergeTreeDataPartType MergeTreeData::choosePartType(size_t bytes_uncompressed, size_t rows_count) const
{
    const auto settings = getSettings();
    if (!canUsePolymorphicParts(*settings))
        return MergeTreeDataPartType::WIDE;
    if (bytes_uncompressed < settings->min_bytes_for_compact_part || rows_count < settings->min_rows_for_compact_part)
        return MergeTreeDataPartType::IN_MEMORY;
    if (bytes_uncompressed < settings->min_bytes_for_wide_part || rows_count < settings->min_rows_for_wide_part)
        return MergeTreeDataPartType::COMPACT;
    return MergeTreeDataPartType::WIDE;
}
MergeTreeDataPartType MergeTreeData::choosePartTypeOnDisk(size_t bytes_uncompressed, size_t rows_count) const
{
    const auto settings = getSettings();
    if (!canUsePolymorphicParts(*settings))
        return MergeTreeDataPartType::WIDE;
    if (bytes_uncompressed < settings->min_bytes_for_wide_part || rows_count < settings->min_rows_for_wide_part)
        return MergeTreeDataPartType::COMPACT;
    return MergeTreeDataPartType::WIDE;
}
MergeTreeData::MutableDataPartPtr MergeTreeData::createPart(const String & name,