```sql
create table dat (blockNum Decimal(10,0), eventTimestamp DateTime64(9) ) 
Engine=MergeTree() primary key eventTimestamp;
insert into dat values (1, '2022-01-24 02:30:00.008122000');

CREATE DICTIONARY datDictionary
(
    `blockNum` Decimal(10, 0),
    `eventTimestamp` DateTime64(9)
)
PRIMARY KEY blockNum
SOURCE(CLICKHOUSE(TABLE 'dat'))
LIFETIME(MIN 0 MAX 1000)
LAYOUT(FLAT());

select * from datDictionary;
┌─blockNum─┬────────────────eventTimestamp─┐
│        1 │ 2022-01-24 02:30:00.008122000 │
└──────────┴───────────────────────────────┘

select count(*) from dat where eventTimestamp >= (select eventTimestamp from datDictionary);

Exception on client:
Code: 32. DB::Exception: Attempt to read after eof: while receiving packet from localhost:9000. (ATTEMPT_TO_READ_AFTER_EOF)

Connecting to localhost:9000 as user default.
Code: 210. DB::NetException: Connection refused (localhost:9000). (NETWORK_ERROR)
```

```sql
drop dictionary datDictionary;

CREATE DICTIONARY datDictionary
(
    `blockNum` Decimal(10, 0),
    `eventTimestamp` DateTime64(9)
)
PRIMARY KEY blockNum
SOURCE(CLICKHOUSE(TABLE 'dat'))
LIFETIME(MIN 0 MAX 1000)
LAYOUT(complex_key_hashed());

select count(*) from dat where eventTimestamp >= (select eventTimestamp from datDictionary);

Error on processing query: Code: 32. DB::Exception: Attempt to read after eof: while receiving packet from localhost:9000. (ATTEMPT_TO_READ_AFTER_EOF) (version 22.7.1.1054)

Connecting to localhost:9000 as user default.
Code: 210. DB::NetException: Connection refused (localhost:9000). (NETWORK_ERROR)
```

```sql
select * from datDictionary;
┌─blockNum─┬────────────────eventTimestamp─┐
│        1 │ 2022-01-24 02:30:00.008122000 │
└──────────┴───────────────────────────────┘

select dictGet('datDictionary', 'eventTimestamp', tuple(cast('1','Decimal(10,0)')));
Code: 407. DB::Exception: Received from localhost:9000. DB::Exception: Bad scale of decimal field. (DECIMAL_OVERFLOW)
```

{
    
    if (types.empty())
        return std::make_shared<DataTypeNothing>();
    if (types.size() == 1)
        return types[0];
    
    {
        bool all_equal = true;
        for (size_t i = 1, size = types.size(); i < size; ++i)
        {
            if (!types[i]->equals(*types[0]))
            {
                all_equal = false;
                break;
            }
        }
        if (all_equal)
            return types[0];
    }
    
    
    {
        DataTypes non_nothing_types;
        non_nothing_types.reserve(types.size());
        for (const auto & type : types)