Ctxrule - match does not return expected result

Question

v.11.1.07 - I have created a ctxrule index as detailed below. However, although a query should match on the given document, it does not return. Any ideas?
begin
ctx_ddl.create_preference('ot_lexer', 'basic_lexer');
ctx_ddl.set_attribute('ot_lexer', 'index_stems', 'ENGLOSH');
end;
begin
ctx_ddl.create_section_group('ot_sec_group', 'auto_section_group');
end;
create table ot_profile_test
(profile_id number,
query clob);
create index ot_profile_rule_ndx on ot_profile_test(query)
indextype is ctxsys.ctxrule parameters
('stoplist ctxsys.empty_stoplist
section group ot_sec_group
lexer ot_lexer');
insert into ot_profile_test values(1, '($apple and $pear) and (1 within food)');
commit;
exec ctxsys.ctx_adm.set_parameter('log_directory', '/yourdir');
exec ctx_output.start_log('ot');
exec ctx_output.add_event(ctx_output.event_index_print_rowid);
exec ctx_output.add_event(ctx_output.event_index_print_token);
exec ctx_ddl.sync_index('ot_profile_rule_ndx', '2040M', null, 1, null, ctx_ddl.lock_nowait_error);
exec ctx_output.end_log;Then, run a query:
declare
a clob := 'apple orange pears banana
<metadata>
<indicators>
   <food>1</food>
</indicators>
</metadata>
vn_profile_id number;
begin
select profile_id into vn_profile_id
from ot_profile_test
where matches(query, a) > 0;
dbms_output.put_line(vn_profile_id);
end;
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at line 8Shouldn't profile_id = 1 be returned?
Also, shouldn't the logfile have 2 rows written to $I?
WRITING TOKEN APPLE:((PEAR) = (PEARS)) * ((1) WITHIN FOOD),0
WRITING TOKEN APPLES:((PEAR) = (PEARS)) * ((1) WITHIN FOOD),0

Answer 1

You need to use a basic_wordlist instead of a basic_lexer and ENGLISH instead of ENGLOSH in order to use stemming and your clob (variable a) must be valid html or xml in order to search within sections. Please see the simplified demonstration below.
SCOTT@orcl_11gR2> begin
  2    ctx_ddl.create_preference ('ot_wordlist', 'basic_wordlist');
  3    ctx_ddl.set_attribute ('ot_wordlist', 'stemmer', 'ENGLISH');
  4    ctx_ddl.create_section_group ('ot_sec_group', 'auto_section_group');
  5  end;
  6  /
PL/SQL procedure successfully completed.
SCOTT@orcl_11gR2> create table ot_profile_test
  2    (profile_id  number,
  3       query         clob)
  4  /
Table created.
SCOTT@orcl_11gR2> create index ot_profile_rule_ndx
  2  on ot_profile_test (query)
  3  indextype is ctxsys.ctxrule
  4  parameters
  5    ('stoplist     ctxsys.empty_stoplist
  6        wordlist     ot_wordlist
  7        section group     ot_sec_group')
  8  /
Index created.
SCOTT@orcl_11gR2> insert into ot_profile_test values
  2    (1, '($apple and $pear) and (1 within food)')
  3  /
1 row created.
SCOTT@orcl_11gR2> commit
  2  /
Commit complete.
SCOTT@orcl_11gR2> exec ctx_ddl.sync_index ('ot_profile_rule_ndx')
PL/SQL procedure successfully completed.
SCOTT@orcl_11gR2> declare
  2    a clob :=
  3        '<table>
  4           <fruits>apple orange pears banana</fruits>
  5           <metadata>
  6             <indicators>
  7            <food>1</food>
  8             </indicators>
  9           </metadata>
10         </table>';
11  begin
12    for r in
13        (select profile_id
14         from      ot_profile_test
15         where  matches (query, a) > 0
16         order  by profile_id)
17    loop
18        dbms_output.put_line (r.profile_id);
19    end loop;
20  end;
21  /
1
PL/SQL procedure successfully completed.
SCOTT@orcl_11gR2>