title: Using Dijkstra algorithm with postgreSQL in Ubuntu 11.10
body: <p>I am learning PostgreSQL.
  I am trying to use Dijkstra algorithm after installing pgrouting to Ubuntu 11.10.</p>
  
  <pre><code>CREATE OR REPLACE FUNCTION shortest_path(sql text, source_id integer,
         target_id integer, directed boolean, has_reverse_cost boolean)
  RETURNS SETOF path_result AS
    '$libdir/libdijkstra.dll'
  LANGUAGE 'C' IMMUTABLE STRICT
  </code></pre>
  
  <blockquote>
    <p>ERROR:  could not access file "$libdir/libdijkstra.dll": No such file
    or directory'</p>
  </blockquote>
  
  <p>Please if possible guide me step by step to use it from installation to use.</p>