```sql
drop table if exists src;

create table src( A Int64, B String, C String) Engine=MergeTree order by A
SETTINGS min_bytes_for_wide_part=0;
insert into src values(1, 'one', 'test');

alter table src detach partition tuple();

alter table src modify column B Nullable(String);

alter table src attach partition tuple();
select * from src;
┌─A─┬─B───┬─C────┐
│ 1 │ one │ test │
└───┴─────┴──────┘

alter table src update C = 'test1' where 1 settings mutations_sync=2;

select * from src;
┌─A─┬─B────┬─C─────┐
│ 1 │ ᴺᵁᴸᴸ │ test1 │   -- expected B='one'
└───┴──────┴───────┘
```

```sql
drop table if exists src;
create table src( A String, B String, C String) Engine=MergeTree order by A
SETTINGS min_bytes_for_wide_part=0;
insert into src values('one', 'one', 'test');

alter table src detach partition tuple();

alter table src modify column A LowCardinality(String);

alter table src attach partition tuple();

select * from src;
┌─A───┬─B───┬─C────┐
│ one │ one │ test │
└─────┴─────┴──────┘

alter table src update C = 'test1' where 1 settings mutations_sync=2;

select * from src;

Received exception from server (version 22.9.1):
Code: 49. DB::Exception: Received from localhost:9000. DB::Exception: 
Got empty stream for SerializationLowCardinality keys.: (while reading column A): 
(while reading from part /var/lib/clickhouse/store/11b/11b74812-48b9-4c1f-9bdc-3e7a28137a9e/all_3_3_0_4/ from mark 0 with max_rows_to_read = 1): 
While executing MergeTreeInOrder. (LOGICAL_ERROR)

```

```sql
drop table if exists src;
create table src( A String, B String, C String) Engine=MergeTree order by A
SETTINGS min_bytes_for_wide_part=0;
insert into src values('one', 'one', 'test');

alter table src detach partition tuple();

alter table src modify column A LowCardinality(String);

alter table src attach partition tuple();

select * from src;
┌─A───┬─B───┬─C────┐
│ one │ one │ test │
└─────┴─────┴──────┘

alter table src modify column C LowCardinality(String);

select * from src;

Received exception from server (version 22.9.3):
Code: 49. DB::Exception: Received from localhost:9000. 
DB::Exception: Got empty stream for SerializationLowCardinality keys.: 
```

related https://github.com/ClickHouse/ClickHouse/issues/42083 , https://github.com/ClickHouse/ClickHouse/issues/42074
(basically it's the same one issue, but I opened this one, because I think the root issue is in `alter update`.

it seems `alter update` updates columns.txt for all columns even if they are not participated in the `alter update`.
std::make_unique<MergeListElement>((*ctx->mutate_entry)->table_id, projection_future_part, settings),
                *ctx->holder,
                ctx->time_of_mutation,
                ctx->context,
                ctx->space_reservation,
                false, 
                {},
                projection_merging_params,
                NO_TRANSACTION_PTR,
                ctx->new_data_part.get(),
                ctx->data_part_storage_builder.get(),
                ".tmp_proj");
            next_level_parts.push_back(executeHere(tmp_part_merge_task));
            next_level_parts.back()->is_temp = true;
        }
        
        return true;
    }
private:
    String name;
    MergeTreeData::MutableDataPartsVector parts;
    const ProjectionDescription & projection;
    size_t & block_num;
    MutationContextPtr ctx;
    Poco::Logger * log;
    std::map<size_t, MergeTreeData::MutableDataPartsVector> level_parts;
    size_t current_level = 0;
    size_t next_level = 1;
    
    static constexpr size_t max_parts_to_merge_in_one_level = 10;