They ask you define a single term "Describe a hash join" as a method of determining skill and ability. They don't try with a second question. They've determined that is the best way to determine DBA skill and ability. How unenlightened. A good database support person has problem solving skills, the ability to debug, ability to manage stress, patience and perseverance. I am able to configure and maintain Oracle Data Guard and know RMAN inside out. But I was at a loss to give a good explanation for one single determining question which immediately took me out of the running. I appreciated knowing that this is how they evaluate candidates because it indicated to me that I would be a poor fit in their culture. They offer no benefits or insurance which is a second strike against them. Read up on hash joins before the interview and I guess that you'll get an offer here.