&gt; Also, this is a personal pet peeve of mine: if you are asking what a singleton is in a job interview, you are interviewing for the wrong thing, so no wonder you are getting the wrong interviewees.<p>I have to agree.<p>The database indexing &quot;how&quot; also seems to fall into this; Maybe you understand what the limitations of the decision are, but even this is moving more into Architect or DBA roles.