**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

case PartitionCommand::MoveDestinationType::DISK:
                        movePartitionToDisk(command.partition, command.move_destination_name, command.part, query_context);
                        break;
                    case PartitionCommand::MoveDestinationType::VOLUME:
                        movePartitionToVolume(command.partition, command.move_destination_name, command.part, query_context);
                        break;
                    case PartitionCommand::MoveDestinationType::TABLE:
                        checkPartitionCanBeDropped(command.partition);
                        String dest_database = query_context.resolveDatabase(command.to_database);
                        auto dest_storage = DatabaseCatalog::instance().getTable({dest_database, command.to_table}, query_context);
                        movePartitionToTable(dest_storage, command.partition, query_context);
                        break;
                }
            }
            break;
            case PartitionCommand::REPLACE_PARTITION:
            {
                checkPartitionCanBeDropped(command.partition);
                String from_database = query_context.resolveDatabase(command.from_database);
                auto from_storage = DatabaseCatalog::instance().getTable({from_database, command.from_table}, query_context);
                replacePartitionFrom(from_storage, command.partition, command.replace, query_context);
            }
            break;
            case PartitionCommand::FETCH_PARTITION:
                fetchPartition(command.partition, metadata_snapshot, command.from_zookeeper_path, query_context);
                break;
            case PartitionCommand::FREEZE_PARTITION:
            {
                auto lock = lockForShare(query_context.getCurrentQueryId(), query_context.getSettingsRef().lock_acquire_timeout);
                current_command_results = freezePartition(command.partition, metadata_snapshot, command.with_name, query_context, lock);