title: GraphQL : Error while adding computed fields
body: <p>I am trying to add a computed field to my graphql table &quot;user&quot; in schema &quot;abc&quot; using the hasura API but receiving the following error :</p>
  <pre><code>Saving computed field failed
  in table &quot;abc.user&quot;: in computed field &quot;full_name&quot;: the computed field &quot;full_name&quot; 
  cannot be added to table &quot;abc.user&quot; because the function &quot;abc.fullname&quot; is 
  of type VOLATILE; cannot be added as a computed field
  </code></pre>
  <p>The function is added correctly :</p>
  <pre><code>    CREATE OR REPLACE FUNCTION abc.fullname(userrow abc.user)
      RETURNS TEXT AS $$
  BEGIN
      SELECT userrow.first_name || ' ' || userrow.last_name;
  END;
  $$ LANGUAGE plpgsql;
  </code></pre>
  <p>I am able to select the function &quot;fullname&quot; from the dropdown but getting an error on adding computed field. Any guidance is appreciated. Thank you.</p>
  <p><a href="https://i.stack.imgur.com/n8Lj4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/n8Lj4.png" alt="enter image description here" /></a></p>