title: Fan trap and chasm trap - Database
body: <p>Can anyone tell me what is chasm trap? Perhaps fan trap too as I'm not too clear. Also, please provide easy to understand examples (via Chen notations).</p>
  
  <p><em>My understanding thus far: I understand that Fan trap is M:1:1:M, which suggests the paths between entities is ambiguous.<br>
  I understand that. For example, if M represents Student and the other M represents School then it'll be ambiguous because we don't know which student studies at which school (that's what I understood so far).</em></p>
  
  <p>However, I cannot grasp what is chasm trap. </p>
  
  <p>Also, how can I identify the traps and then fix it? </p>