title: PSQL command-line option to require transactions
body: <p>I'd like to stop myself from doing something stupid.  I'd like to tell <code>psql</code> to reject any DML (updates, inserts) that isn't explicitly enclosed in a transaction.</p>
  
  <pre><code>postgres=# update  "employees" set salary = salary * 1.5;
  ERROR:  cannot update outside of a transaction 
  postgres=# start transaction;
  START TRANSACTION
  postgres=# update  "employees" set salary = salary * 1.5;
  UPDATE 331805
  postgres=# rollback;
  ROLLBACK
  postgres=# 
  </code></pre>
  
  <p>Actually, what would be almost as good (and better in some situations) for me would be an option that forbid psql from executing any DML at all.</p>
  
  <p>(Yes, in a formal sense, I could just "stop doing stupid things", but you know, baby steps.)</p>