Relationship between Fact and Dimension Table - Identifying or non-identifying?

Can the relationship between a dimension table and fact table be identifying as well as non-identfying?

Yes, no, and it doesn't really matter.

In a logical model, any dimension which is part of the fact grain would be considered identifying. Any dimension which further describes that grain would be considered non-identifying.

Whether you enforce this in your physical design may depend on how you handle your ETL.

A relationship is either identifying or non-identifying. It cannot be both (i.e. mutually exclusive). Both are valid in a dimensional model.

Thanks for the replies.
I understand it now.

Especially the explanation given by Bob is very helpful. I now get the concept well.
And BoxesAndLines, I understand that a relationship can either be identifying or non-identifying at a time. My question was a bit misleading. I actually thought the relationships between dimension tables and fact table should always be identifying. I now understand that it can be either.

Two clarifications I seek from you all is :
1. whether inclusion of some flags and numeric attributes apart from the FKs of dimension tables in the primary key of Fact table normal?
2. If I group these numeric attributes and flags that are part of the primary key in a junk dimension and join this junk dimension with the fact table through identifying relationship, will this be part of the key of the fact table?