I am learning PostgreSQL. I am trying to use Dijkstra algorithm after installing pgrouting to Ubuntu 11.10.
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
$libdir/libdijkstra.dll
LANGUAGE C IMMUTABLE STRICT
ERROR: could not access file "$libdir/libdijkstra.dll": No such file or directory
如果可能,请指导我一步一步地使用它,从安装到使用。