MySQL optimizations. what happens behind the scenes?

Hi.

I'm using the latest Phalcon build and I need a few tips regarding MySQL optimization and general ORM questions:

1. Is there any kind of type mapping? so int's will be int and not a string.
2. How can I use the default colunm values normally? can it happen without the Raw-something shit I found on Google?
3. Not really related but is there a Phalcon PHP7 progress bar somewhere? I found some github discussions but no one has an updated timeline.
4. I configured my relational database both in MySQL and inside the model (using hasMany/belongsTo), but I couldn't find out what happens behind the scenes when you use it? I'll take the robots example from the docs https://docs.phalcon.io/en/latest/reference/models.html

$robots = Robots::find(); foreach ($robots as $robot) $robotsParts = $robot->getRobotsParts();

Does it query every time I call getRobotsParts or automatically joins allways. How can I optimize it? where can I know more about it and how it works?

P.S All optimization tips are welcome :)

Thanks.