I wanted to generate 2 differnet kinds of Classes both mapped to the same table. Is there any thing that keeps me from doing this? ( I think not, but wanted to ask)

Table Person {
ID, (PK)
Fname,
LastName
Phone,
Address,
}

Class BriefPerson {
Integer PK
String LName
String Phone
}

and

Class Person {
..
all columns
..
}

So when I wanted a BriefPerson colleciton of all I am just getting a few
of the column and No collections no extra attributes.

Try the Lightweight Class pattern: http://www.hibernate.org/41.html