When you show up in Alberta and want to get licensed as a new driver and do not have an existing drivers license from another country, what will happen is this:
You will be placed in the graduated drivers license program where you are allowed a learners permit (class 7) after passing the written exam. You will then only be allowed to drive with another fully licensed person with you in the car. You need to wait a year until you are allowed to take the basic road test and get a GDL license which will allow you to drive by yourself.
The difference if you have a full license from another country, even if you can not prove driving experience is that you would then be allowed to take the basic road test without waiting a year and get a GDL license.
So.. it's up to you if you want to wait a year or not.
If you go for the Vietnamese license, you need to either get it translated into English by a certified translator or get an international license in Vietnam to bring with you to Canada to prove that what you have in your hand is a drivers license and not a library card.
Here's some info on exchanging a non-AB drivers license: http://www.servicealberta.gov.ab.ca/drivers_licence.cfm#Exchanging_a_Non-Alberta_Operators_Licence