Who is poliana?

I think you may be referring to "Pollyanna." She was the heroine of a popular children's book, way back in 1913. To this day, while the book may be forgotten, the character is not. Pollyanna was a girl who had a totally positive outlook no matter what happened in her life. And to this day, a person who always looks on the bright side has come to be called a "Pollyanna." (By the way, it is not always used as a compliment-- rather, it carries a meaning of a person who is unrealistically positive, or refuses to accept how bad things are.)