```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)
```

{
    return typeid_cast<const DataTypeDecimal<T> *>(&data_type);
}
inline UInt32 getDecimalScale(const IDataType & data_type, UInt32 default_value = std::numeric_limits<UInt32>::max())
{
    if (const auto * decimal_type = checkDecimal<Decimal32>(data_type))
        return decimal_type->getScale();
    if (const auto * decimal_type = checkDecimal<Decimal64>(data_type))
        return decimal_type->getScale();
    if (const auto * decimal_type = checkDecimal<Decimal128>(data_type))
        return decimal_type->getScale();
    if (const auto * decimal_type = checkDecimal<Decimal256>(data_type))
        return decimal_type->getScale();
    return default_value;
}
inline UInt32 getDecimalPrecision(const IDataType & data_type)
{
    if (const auto * decimal_type = checkDecimal<Decimal32>(data_type))
        return decimal_type->getPrecision();
    if (const auto * decimal_type = checkDecimal<Decimal64>(data_type))
        return decimal_type->getPrecision();
    if (const auto * decimal_type = checkDecimal<Decimal128>(data_type))
        return decimal_type->getPrecision();
    if (const auto * decimal_type = checkDecimal<Decimal256>(data_type))
        return decimal_type->getPrecision();
    return 0;
}
template <typename T>
inline UInt32 getDecimalScale(const DataTypeDecimal<T> & data_type)