title: What is more efficient, case statement or if elseif etc in PL/SQL
body: <p>examples are:</p>
  
  <pre><code>CASE
      WHEN selector = 'value1' THEN S1;
      WHEN selector = 'value2' THEN S2;
      WHEN selector = 'value3' THEN S3;
      ...
      ELSE Sn;  -- default case
  END CASE;
  </code></pre>
  
  <p>or another:</p>
  
  <pre><code>IF(boolean_expression 1)THEN 
     S1; -- Executes when the boolean expression 1 is true 
  ELSIF( boolean_expression 2) THEN
     S2;  -- Executes when the boolean expression 2 is true 
  ELSIF( boolean_expression 3) THEN
     S3; -- Executes when the boolean expression 3 is true 
  ELSE 
     S4; -- executes when the none of the above condition is true 
  END IF;
  </code></pre>