advanced queuing for table replication to other database

So, I am trying to replicate the data in tables to another database using Advanced Queuing. I created a table on both databases:

create table test
(
  id number(10) primary key,
  text varchar2(100)
);

then I created the queue

create type table_repli_payload_type AS OBJECT
(   rowid_record   varchar2(100)
  , tabelle        VARCHAR2(255)
  , schema         VARCHAR2(50)
);



begin
  SYS.DBMS_AQADM.create_queue_table(queue_table        => 'table_repli_queue_table',
        queue_payload_type => 'table_repli_payload_type',
        multiple_consumers => TRUE);
   SYS.DBMS_AQADM.CREATE_QUEUE (
          queue_name  => 'table_repli_queue',
          queue_table => 'table_repli_queue_table'
          );
       SYS.DBMS_AQADM.START_QUEUE (
          queue_name => 'table_repli_queue'
          );
end;

wrote a procedure for the replication

create or replace procedure table_repli_callback(
                 context  RAW,
                 reginfo  SYS.AQ$_REG_INFO,
                 descr    SYS.AQ$_DESCRIPTOR,
                 payload  RAW,
                 payloadl NUMBER
                 ) AS

   r_dequeue_options    DBMS_AQ.DEQUEUE_OPTIONS_T;
   r_message_properties DBMS_AQ.MESSAGE_PROPERTIES_T;
   v_message_handle     RAW(16);
   o_payload            table_repli_payload_type;
   v_error varchar2(4000);

BEGIN
   insert into log_table values(sysdate, 'start table_repli_callback');
   r_dequeue_options.msgid := descr.msg_id;
   r_dequeue_options.consumer_name := descr.consumer_name;

   DBMS_AQ.DEQUEUE(
      queue_name         => descr.queue_name,
      dequeue_options    => r_dequeue_options,
      message_properties => r_message_properties,
      payload            => o_payload,
      msgid              => v_message_handle
      );
    insert into log_table values(sysdate, 'ROWID: '||o_payload.rowid_record);

    merge into test@test_link a
    using (select * from test where rowid=o_payload.rowid_record) b on (a.id=b.id)
    when matched then
    update set text=b.text
    when not matched then
      insert values(b.id, b.text);

   COMMIT;
exception
  when others then
    v_error:=sqlerrm;
    insert into log_table values(sysdate, 'ERROR: '||v_error);
    commit;    
END;
/

and subscribed it

BEGIN
   DBMS_AQADM.ADD_SUBSCRIBER (
      queue_name => 'table_repli_queue',
      subscriber => SYS.AQ$_AGENT(
                       'table_repli_queue_subscriber',
                       NULL,
                       NULL )
      );
    DBMS_AQ.REGISTER (
       SYS.AQ$_REG_INFO_LIST(
          SYS.AQ$_REG_INFO(
             'table_repli_queue:table_repli_queue_subscriber',
             DBMS_AQ.NAMESPACE_AQ,
             'plsql://table_repli_callback',
             HEXTORAW('FF')
             )
          ),
       1
       );
END;
/

I played around with inserting/updating data in the TEST-table and than executing(with changing ids) this Code

DECLARE
   r_enqueue_options    DBMS_AQ.ENQUEUE_OPTIONS_T;
   r_message_properties DBMS_AQ.MESSAGE_PROPERTIES_T;
   v_message_handle     RAW(16);
   o_payload            table_repli_payload_type;
   v_rowid_record varchar2(100);
BEGIN
   select rowid
     into v_rowid_record
     from test
     where id=2;
   o_payload := table_repli_payload_type(
                   v_rowid_record, '', ''
                   );
   DBMS_AQ.ENQUEUE(
      queue_name         => 'table_repli_queue',
      enqueue_options    => r_enqueue_options,
      message_properties => r_message_properties,
      payload            => o_payload,
      msgid              => v_message_handle
      );
  COMMIT;
END;
/

It's pretty random if it is working. He always seems to write something into TABLE_REPLI_QUEUE_TABLE, but when it is gone, about half the time there doesn't appear anything in LOG_TABLE and the data in the second database hasn't changed.

The error was a strange behavior in TOAD. I sometimes write test scripts, with ddl, dml, selects, pl/sql-blocks in it and execute them by placing my cursor in a part of the desired command and press shift+F9. It seems like my TOAD just didn't execute the PL/SQL-block although it told me, it did. I put the PL/SQL-block in another tab and just hit F9 and it worked fine, every time.