Please help explain strange behaviour of progressive relaxation..

Question

Hello
I am building theo Oracle text querry and I stumbled on a behaviour which I cannot explain...
here is the topo:
I have created a synonym thusly:
ctx_thes.create_relation('GR_THESAURUS','LEBOURGNEUF','SYN','BOURGNEUF');
when I issue this select:
SELECT      SCORE(1) NIVEAU_RECHERCHE, NOM,NO_MATRC,NO_NOM_REGST
FROM DUMMY
WHERE CONTAINS(nom, 'SYN(LEBOURGNEUF, GR_THESAURUS)', 1) > 0 ;
I get the expected result set which containsentries with either 'LEBOURGNEUF' or 'BOURGNEUF'. So far so good.
Now, when I combine search criterias using progressive relaxation, thus:
SELECT SCORE(1) NIVEAU_RECHERCHE, DUMMY.NO_MATRC,DUMMY.NO_NOM_REGST,DUMMY.NOM
FROM DUMMY
WHERE CONTAINS(nom, '<query>
<textquery lang="FRENCH" grammar="CONTEXT">LEBOURGNEUF golf
<progression>
<seq><rewrite>transform((TOKENS, "{", "}", "AND"))</rewrite></seq>
<seq><rewrite>transform((TOKENS, "{", "}", "OR"))</rewrite></seq>
<seq><rewrite>transform((TOKENS, "SYN(", ",GR_THESAURUS)", "OR"))</rewrite></seq>
</progression>
</textquery>
<score datatype="INTEGER" algorithm="DEFAULT"/>
</query>', 1) > 0;
I do NOT get any results matching synonym 'BOURGNEUF'.. only those with 'LEBOURGNEUF' are returned...
further, if I intentionaly make a syntax error in the line
<seq><rewrite>transform((TOKENS, "SYN(", ",GR_THESAURUS)", "OR"))</rewrite></seq>
say like this:
<seq><rewrite>transform((TOKENS, "xSYN(", ",GR_THESAURUS)", "OR"))</rewrite></seq>
no error is returned and I get the same result set...
so this leads me to conclude that only the first two lines of the query are parsed/executed...
does anyone here have any ideas what is going one here?
in the preceding quire I neeed to add
                                                  <seq><rewrite>transform((TOKENS, "SYN(", ",GR_THESAURUS)", "AND"))</rewrite></seq>
<seq><rewrite>transform((TOKENS, "SYN(", ",GR_THESAURUS)", "OR"))</rewrite></seq>
and possibly
<seq><rewrite>transform((TOKENS, "NT(", ",2,GR_THESAURUS)", "OR"))</rewrite></seq>
can this be done???
why is there no errors when I execute the query (in sqldeveloper) ???
any hints will be greatly appreciated!
Cheers
Edited by: user8848610 on 2009-10-29 07:46

Answer 1

now it works... although the simpler and cleaner solution of using transform would have been perfect, this function does a somewhat adequate job... I put it here so maybe it will help others ;)
     FUNCTION BuildSearchPredicate (texte IN NOM_ASSJT.NOM%TYPE) RETURN VARCHAR2 IS
     sSQL VARCHAR2(5000);
     sSeq1 VARCHAR2(1000);
     sSeq2 VARCHAR2(1000);
     sSeq3 VARCHAR2(1000);
     iFirst NUMBER(1);
     iPosition NUMBER;
     iToken NUMBER;
     CURSOR curWords(line_text IN VARCHAR2)      IS      
               select regexp_substr(line_text, '[^ ]+', 1, level) word
               from dual
               connect by regexp_substr(line_text, '[^ ]+', 1, level) is not null;
     BEGIN
     sSQL := sSQL || '<query><textquery lang="FRENCH" grammar="CONTEXT"><progression> ';
     sSeq1 := '';
     iFirst := 1;
     iToken := 0;
     FOR r_curWord IN curWords(texte)
     LOOP
     iToken := iToken + 1;
     IF iFirst = 0 THEN
               sSeq1 := sSeq1 || ' AND {' || trim(r_curWord.word) || '}';
               sSeq2 := sSeq2 || ' OR {' || trim(r_curWord.word) || '}';
               sSeq3 := sSeq3 || ' OR SYN(' || trim(r_curWord.word) || ',GR_THESAURUS)';
          ELSE
               sSeq1 := '{' || trim(r_curWord.word) || '}';
               sSeq2 := '{' || trim(r_curWord.word) || '}';
               sSeq3 := 'SYN(' || trim(r_curWord.word) || ',GR_THESAURUS)';
               iFirst := 0;
          END IF;
     END LOOP;
     sSQL := sSQL || '<seq>' || sSeq1 || '</seq>';
     iPosition := instr(sSeq1, ' AND ');
     IF instr(sSeq1, ' AND ',iPosition + 1) > 0 THEN -- we must have at least 2 AND operator for this to make sense
          WHILE iPosition > 0
          LOOP
IF instr(substr(sSeq1, iPosition + 5), ' AND ') > 0 THEN
sSQL := sSQL || '<seq>' || substr(sSeq1, iPosition + 5) || '</seq>';
END IF;
               iPosition := instr(sSeq1, ' AND ', iPosition + 1);
          END LOOP;
     END IF;
     IF iToken > 1 THEN -- no use in having OR if there is only one word
          sSQL := sSQL || '<seq>' || sSeq2 || '</seq>';
     END IF;
     sSQL := sSQL || '<seq>' || sSeq3 || '</seq>';
     RETURN sSql;
     END BuildSearchPredicate;     
END GR_RECH;
this will combine search words using AND and OR and SYN like so:
SELECT GR_RECH.BuildSearchPredicate('LEBOURGNEUF GOLF') FROM DUAL;
will result in :
<query><textquery lang="FRENCH" grammar="CONTEXT"><progression> <seq>{LEBOURGNEUF} AND {GOLF}</seq><seq>{LEBOURGNEUF} OR {GOLF}</seq><seq>SYN(LEBOURGNEUF,GR_THESAURUS) OR SYN(GOLF,GR_THESAURUS)</seq>
thanks for you help!
cheers
gth