**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

}
    }
    
    
    auto table_id = getStorageID();
    if (auto part_log = global_context.getPartLog(table_id.database_name))
    {
        PartLogElement part_log_elem;
        part_log_elem.event_type = PartLogElement::REMOVE_PART;
        part_log_elem.event_time = time(nullptr);
        part_log_elem.duration_ms = 0;
        part_log_elem.database_name = table_id.database_name;
        part_log_elem.table_name = table_id.table_name;
        for (const auto & part : parts)
        {
            part_log_elem.partition_id = part->info.partition_id;
            part_log_elem.part_name = part->name;
            part_log_elem.bytes_compressed_on_disk = part->getBytesOnDisk();
            part_log_elem.rows = part->rows_count;
            part_log->add(part_log_elem);
        }
    }
}
void MergeTreeData::clearOldPartsFromFilesystem(bool force)
{
    DataPartsVector parts_to_remove = grabOldParts(force);
    clearPartsFromFilesystem(parts_to_remove);
    removePartsFinally(parts_to_remove);
}
void MergeTreeData::clearPartsFromFilesystem(const DataPartsVector & parts_to_remove)