title: Unique row identifier in Presto SQL
body: <p>I work on Presto SQL tables that don't have unique row identifiers. The only way to identify a specific record is to query all of its fields.</p>
  
  <p>Is there in Presto some kind of hidden field, say <code>ROW_PRIMARY_KEY</code>, that would allow me to uniquely identify records in my tables?</p>