text: Q:
  
  Relational Algebra - Select with no predicate
  
  I know about relational algebra, but with regard to the select part of it, what should I say if there isn't any specific condition.
  For example I have a Hotels Table and I just want to output that result.
  Should I just use σ(Hotels) or do I need to put something like σALL(Hotels)???
  I need your help!
  
  A:
  
  Use Reference(R) if you dont have any condition
  Reference Refers to an existing relation.
  Algebra: R
  SQL: SELECT * FROM table
  Examples: SELECT * FROM Hotels
  Returns every tuple in the Member table that you need. (No particular order is requested or implied.)
  If you need to apply any condition only then use 
  σ<selection condition>(R)
  
  Ref: http://bohr.wlu.ca/cp363/notes/theory/relational_algebra.php 
  
  