**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 (column_info_it != columns_info.end())
            {
                if (columns_mask[src_index++])
                    columns[res_index++]->insert(column_info_it->second.default_kind);
                if (columns_mask[src_index++])
                    columns[res_index++]->insert(column_info_it->second.default_expression);
            }
            else
            {
                if (columns_mask[src_index++])
                    columns[res_index++]->insertDefault();
                if (columns_mask[src_index++])
                    columns[res_index++]->insertDefault();
            }
            ColumnSize column_size = part->getColumnSize(column.name, *column.type);
            if (columns_mask[src_index++])
                columns[res_index++]->insert(column_size.data_compressed + column_size.marks);
            if (columns_mask[src_index++])
                columns[res_index++]->insert(column_size.data_compressed);
            if (columns_mask[src_index++])
                columns[res_index++]->insert(column_size.data_uncompressed);
            if (columns_mask[src_index++])
                columns[res_index++]->insert(column_size.marks);
            if (has_state_column)
                columns[res_index++]->insert(part->stateString());
        }
    }
}
}