title: How to get a real time within PostgreSQL transaction?
body: <p>As far as I understand <em>now()</em> returns the same time during the whole PostgreSQL transaction?
  But how to get <strong>real</strong> time?</p>
  
  <p>Also, I am interested if there any configuration parameter to limit duration of transaction, so that after this period expiration transaction would immediately fail or somehow else prohibit following queries?</p>