**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

for (const auto * child : action.node->children)
                columns_alter_type_forbidden.insert(child->result_name);
        }
        
        for (const String & col : partition_key_expr->getRequiredColumns())
            columns_alter_type_check_safe_for_partition.insert(col);
    }
    for (const auto & index : old_metadata.getSecondaryIndices())
    {
        for (const String & col : index.expression->getRequiredColumns())
            columns_alter_type_forbidden.insert(col);
    }
    if (old_metadata.hasSortingKey())
    {
        auto sorting_key_expr = old_metadata.getSortingKey().expression;
        for (const auto & action : sorting_key_expr->getActions())
        {
            for (const auto * child : action.node->children)
                columns_alter_type_forbidden.insert(child->result_name);
        }
        for (const String & col : sorting_key_expr->getRequiredColumns())
            columns_alter_type_metadata_only.insert(col);
        
        
    }
    if (!merging_params.sign_column.empty())
        columns_alter_type_forbidden.insert(merging_params.sign_column);
    
    NameSet columns_in_keys;
    columns_in_keys.insert(columns_alter_type_forbidden.begin(), columns_alter_type_forbidden.end());