pg_cancel_backend() does not work with buzz queries

Hi all,

I often face with buzz queries (see below). I've looked through pg
manual and huge amount of forums and mail archives and found nothing.
The only solution  is to restart postgres server. Moreover I have to
terminate the process using HUP signal to stop the server.

transport=# select version();
                                       version
-------------------------------------------------------------------------------------
 PostgreSQL 8.2.4 on i686-pc-linux-gnu, compiled by GCC gcc (GCC)
3.3.3 (SuSE Linux)
(1 row)

transport=# select datname, usename, procpid, current_query::char(15),
waiting, query_start from pg_catalog.pg_stat_activity where procpid =
20530;
  datname  |     usename      | procpid |  current_query  | waiting |
        query_start
-----------+------------------+---------+-----------------+---------+-------------------------------
 transport | belostotskaya_la |   20530 | select * from c | f       |
2007-10-02 05:05:28.908687+04
(1 row)

transport=# select pg_catalog.pg_cancel_backend(20530);
 pg_cancel_backend
-------------------
 t
(1 row)

transport=# select datname, usename, procpid, current_query::char(15),
waiting, query_start from pg_catalog.pg_stat_activity where procpid =
20530;
  datname  |     usename      | procpid |  current_query  | waiting |
        query_start
-----------+------------------+---------+-----------------+---------+-------------------------------
 transport | belostotskaya_la |   20530 | select * from c | f       |
2007-10-02 05:05:28.908687+04
(1 row)

--
Regards,
Sergey Konoplev