Oracle Text with User_DataStore is not working

Question

Hi Expert,
Based on this url  : http://docs.oracle.com/cd/B28359_01/text.111/b28304/cdatadic.htm#i1006810
I was trying to create an oracle text index , but i wasn't able to retrieve the data
here are my scripts:
create table articles(
    id       number,
    author   varchar2(80),
    title    varchar2(120),
    text     clob );
    create procedure myproc(rid in rowid, tlob in out clob nocopy) is
  begin
      for c1 in (select author, title, text from articles
                  where rowid = rid)
      loop
      dbms_lob.writeappend(tlob, length(c1.title), c1.title);
   dbms_lob.writeappend(tlob, length(c1.author), c1.author);
   dbms_lob.writeappend(tlob, length(c1.text), c1.text);
       end loop;
    end;
    begin
ctx_ddl.create_preference('myud', 'user_datastore');
ctx_ddl.set_attribute('myud', 'procedure', 'myproc');
ctx_ddl.set_attribute('myud', 'output_type', 'CLOB');
end;
    create index myindex2 on articles(text)
  indextype is ctxsys.context
  parameters ('DATASTORE myud'); 
      insert into articles(id,author,title)values (1,'A','AAAAAA');commit;
      insert into articles(id,author,title)values (2,'B','BBBBBB');commit;
      insert into articles(id,author,title)values (3,'C','CCCCCC');commit;
      insert into articles(id,author,title)values (4,'D','DDDDDD');commit;
      EXEC CTX_DDL.SYNC_INDEX('myindex2','2M');
      select * from articles where contains(text,'B',1)>0;  -- this display nothing.
Can anybody help me?

Answer 1

It's absolutly essential to get into the details of Oracle Text if it is used for more than pretty simple things.
Query the index tables and view the tokens stored.
Is there any token like 'B'?
I guess no. Because your function constructs something other ...
What do you get, if you try 'B%' instead of 'B'?