**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

}
            break;
            case PartitionCommand::FREEZE_ALL_PARTITIONS:
            {
                auto lock = lockForShare(query_context.getCurrentQueryId(), query_context.getSettingsRef().lock_acquire_timeout);
                current_command_results = freezeAll(command.with_name, metadata_snapshot, query_context, lock);
            }
            break;
            case PartitionCommand::UNFREEZE_PARTITION:
            {
                auto lock = lockForShare(query_context.getCurrentQueryId(), query_context.getSettingsRef().lock_acquire_timeout);
                current_command_results = unfreezePartition(command.partition, command.with_name, query_context, lock);
            }
            break;
            case PartitionCommand::UNFREEZE_ALL_PARTITIONS:
            {
                auto lock = lockForShare(query_context.getCurrentQueryId(), query_context.getSettingsRef().lock_acquire_timeout);
                current_command_results = unfreezeAll(command.with_name, query_context, lock);
            }
            break;
        }
        for (auto & command_result : current_command_results)
            command_result.command_type = command.typeToString();
        result.insert(result.end(), current_command_results.begin(), current_command_results.end());
    }
    if (query_context.getSettingsRef().alter_partition_verbose_result)
        return convertCommandsResultToSource(result);
    return {};
}
String MergeTreeData::getPartitionIDFromQuery(const ASTPtr & ast, const Context & context) const