It depends on such diverse factors as your research direction, your supervisor(s), universities' policies, your own department, your previous academic performance, etc.
I know pursuing a phd is a difficult decision to make for everyone, but my suggestion is unless you really know what is meant to you, do not do it because you are openning a door to struggle and frustration for at least 5 years.
Thank you very much for your excellent suggestions!
I have no idea about total financial support for the whole program. At least how much in one academic year in generally? 20,000CAD OR MORE?
I know it is a hard decision if I decide to do it. The sad news that I heard are some PHDs graduated from the school but can't find specialty job. Some PHDs do the labour job, is it right?