**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 (old_metadata.getColumns().has(command.column_name))
                {
                    columns_to_check_conversion.push_back(
                        new_metadata.getColumns().getPhysical(command.column_name));
                }
            }
        }
    }
    checkProperties(new_metadata, old_metadata);
    checkTTLExpressions(new_metadata, old_metadata);
    if (!columns_to_check_conversion.empty())
    {
        auto old_header = old_metadata.getSampleBlock();
        performRequiredConversions(old_header, columns_to_check_conversion, global_context);
    }
    if (old_metadata.hasSettingsChanges())
    {
        const auto current_changes = old_metadata.getSettingsChanges()->as<const ASTSetQuery &>().changes;
        const auto & new_changes = new_metadata.settings_changes->as<const ASTSetQuery &>().changes;
        for (const auto & changed_setting : new_changes)
        {
            const auto & setting_name = changed_setting.name;
            const auto & new_value = changed_setting.value;
            MergeTreeSettings::checkCanSet(setting_name, new_value);
            const Field * current_value = current_changes.tryGet(setting_name);
            if ((!current_value || *current_value != new_value)
                && MergeTreeSettings::isReadonlySetting(setting_name))
            {
                throw Exception{"Setting '" + setting_name + "' is readonly for storage '" + getName() + "'",