title: postgresql, insert several sets of 3 items with 2 same item in every set
body: <p>I need to insert several sets of 3 items. 2 items are the same in every set.
  I want to put at position of $1 this clause: EXTRACT(EPOCH FROM NOW() AT TIME ZONE 'UTC')</p>
  
  <pre><code>WITH data(serial_id, banned_ts, reason) AS (
      VALUES (x, $1, $2),(y, $1, $2),(z, $1, $2)
      )
      INSERT INTO _serial_ids_banned (serial_id, banned_ts, reason)
      SELECT d.serial_id, d.banned_ts, d.reason
      FROM data d
      WHERE NOT EXISTS
          (SELECT 1 FROM _serial_ids_banned b
          WHERE b.serial_id = d.serial_id);
  </code></pre>
  
  <p>If I do it then the clause will be evaluated 3 times(or more depending on number of the sets). Is it possible to create such a query that will evaluate the clause only once and use it in every set?</p>