title: Inserting record violates two unique indices in PostgreSQL. Which one is checked first?
body: <p>I have a PostgreSQL table with two unique indices on different fields (<code>nickname</code> and <code>email</code>). I'm trying to insert a record which violates both constraints. I want that <code>nickname</code> is checked and reported first.</p>
  
  <p>I observed that the index that was created first is checked first, so I create the index on <code>nickname</code> first and it kind of works. But is that behavior specified and can I rely upon it, or is it only by chance?</p>