**Describe the bug**

I have a table like:

```
CREATE TABLE test (
    time DateTime64(3)
    ...
) ENGINE = MergeTree()
PARTITION BY toStartOfInterval(time, INTERVAL 1 HOUR)
...
```

But when I search in `system.parts` it does not appear to have the `min/max` columns appropriately set?

```
partition:                             2020-06-01 01:00:00
min_date:                              1970-01-01
max_date:                              1970-01-01
min_time:                              1970-01-01 00:00:00
max_time:                              1970-01-01 00:00:00
```

I assume that if these were correctly set, doing a `select toStartOfInterval(time, interval 1 day), count()` type query would be pretty instant rather than trying to scan everything? I am guessing this is due to the `DateTime64` type in use?

Clickhouse 20.11.3.3

{
    if (from->getName() == to->getName())
        return true;
    
    
    
    if (const auto * from_enum8 = typeid_cast<const DataTypeEnum8 *>(from))
    {
        if (const auto * to_enum8 = typeid_cast<const DataTypeEnum8 *>(to))
            return to_enum8->contains(*from_enum8);
        if (typeid_cast<const DataTypeInt8 *>(to))
            return true;    
        return false;
    }
    if (const auto * from_enum16 = typeid_cast<const DataTypeEnum16 *>(from))
    {
        if (const auto * to_enum16 = typeid_cast<const DataTypeEnum16 *>(to))
            return to_enum16->contains(*from_enum16);
        if (typeid_cast<const DataTypeInt16 *>(to))
            return true;    
        return false;
    }
    if (const auto * from_lc = typeid_cast<const DataTypeLowCardinality *>(from))
        return from_lc->getDictionaryType()->equals(*to);
    if (const auto * to_lc = typeid_cast<const DataTypeLowCardinality *>(to))
        return to_lc->getDictionaryType()->equals(*from);
    return false;
}
void checkVersionColumnTypesConversion(const IDataType * old_type, const IDataType * new_type, const String column_name)