title: trigger or computed field
body: <p>I wonder when I want to display result of calculating some fields in the same table should I do it as computed field or by using "before insert or update" trigger ?. </p>
  
  <p>Note: I found similar question but it was for SQL Server and I need to know when I display the result in a grid with many records visible, if the computed field will affect performance in this case.  </p>
  
  <p>Example of the calculation I use now in a computed field:</p>
  
  <pre><code>field_1 * (
    iif(field_2 is null,0,1)
   +iif(field_3 is null,0,1)
   +iif(field_4 is null,0,1)
   +iif(field_5 is null,0,1))
  </code></pre>