reated for table columns of
   range types.  For these index types, basically the only useful range
   operation is equality.  There is a B-tree sort ordering defined for range
   values, with corresponding <code class="literal">&lt;</code> and <code class="literal">&gt;</code> operators,
   but the ordering is rather arbitrary and not usually useful in the real
   world.  Range types' B-tree and hash support is primarily meant to
   allow sorting and hashing internally in queries, rather than creation of
 