 <span class="productname">Informix</span>
   behavior; it allows you to do more or less the same operations and gives
   you functions that have the same name and the same basic behavior but it is
   no drop-in replacement if you are using <span class="productname">Informix</span> at the moment. Moreover,
   some of the data types are different. For example,
   <span class="productname">PostgreSQL</span>'s datetime and interval types do not
   know about ranges like for example <code class="literal">YEAR T