When interviewing with the organization's technical staff, the worst thing you could do is try to bluff your way through an answer. The interviewers will quickly recognize your lack of knowledge and will precede to challenge you with more difficult questions to confirm this. If you don't know the answer to a question, admit this to the interviewer, then describe how you would either learn the concept or where you could find the information they were asking you about. Interviewers value honesty more than creativity during the interview.

"Hierarchy flattening involves the creation of parent/child relationship hierarchies. It results in a description of hierarchy in either the vertical or horizontal format. The hierarchy pattern includes attributes and columns for both the parent and child columns. The purpose of hierarchy fattening is to provide a clear understanding of the basic hierarchy of business intelligence."