"Huy Do" <huy(at)travel(dot)com(dot)au> writes:
> is there any major disadvantages of changing all my char fields to
> varchar fields
No. Stop worrying about micro-optimization and instead worry about
picking the data type that describes the semantics of your data.
If the presence or absence of a trailing space makes a difference
to you, then you should be using varchar (or text).
regards, tom lane