CREATE INDEX IDX_EXTRACT_TITRE
ON TABLE_TITLE (Titre) INDEXTYPE IS CTXSYS.CONTEXT
PARAMETERS ('DATASTORE DS_EXTRACT_TITRE LEXER LX_EXTRACT_TITRE FILTER FILTER_EXTRACT_TITRE STORAGE STORAGE_EXTRACT_TITRE WORDLIST WORDLIST_EXTRACT_TITRE');

CREATE OR REPLACE TRIGGER TU_TABLE_TITLE
AFTER INSERT OR UPDATE OR DELETE ON TABLE_TITLE
DECLARE
  v_job NUMBER;
BEGIN
  IF deleting THEN
    DBMS_JOB.SUBMIT(v_job, 'ctx_ddl.optimize_index(''IDX_EXTRACT_TITRE
'',''FULL'');', SYSDATE);
  ELSE
    DBMS_JOB.SUBMIT(v_job, 'ctx_ddl.sync_index(''IDX_EXTRACT_TITRE');', SYSDATE);
  END IF;
END;
/
show errors;
/

 UPDATE TABLE_TITLE
    SET titre = 'BLA BLO BLI'
  WHERE key=<keyValue>;
 
COMMIT;
 
SELECT count(*) FROM TABLE_TITLE WHERE CONTAINS(TITRE, 'BLA') > 0  (returns 0 line)

SCOTT@orcl_11g> CREATE TABLE table_title
  2    (key    NUMBER,
  3  	title  CLOB)
  4  /

Table created.

SCOTT@orcl_11g> INSERT INTO table_title VALUES (1, 'test title')
  2  /

1 row created.

SCOTT@orcl_11g> CREATE INDEX idx_extract_title
  2  ON table_title (title)
  3  INDEXTYPE IS CTXSYS.CONTEXT
  4  /

Index created.

SCOTT@orcl_11g> CREATE OR REPLACE TRIGGER tu_table_title
  2    AFTER INSERT OR UPDATE OR DELETE ON table_title
  3  DECLARE
  4    v_job NUMBER;
  5  BEGIN
  6    IF deleting THEN
  7  	 DBMS_JOB.SUBMIT
  8  	   (v_job,
  9  	    'ctx_ddl.optimize_index(''IDX_EXTRACT_title'',''FULL'');',
 10  	    SYSDATE);
 11    ELSE
 12  	 DBMS_JOB.SUBMIT
 13  	   (v_job,
 14  	    'ctx_ddl.sync_index(''IDX_EXTRACT_title'');',
 15  	    SYSDATE);
 16    END IF;
 17  END tu_table_title;
 18  /

Trigger created.

SCOTT@orcl_11g> SHOW ERRORS
No errors.
SCOTT@orcl_11g> UPDATE table_title
  2  SET    title = 'BLA BLO BLI'
  3  WHERE  key = 1
  4  /

1 row updated.

SCOTT@orcl_11g> COMMIT
  2  /

Commit complete.

SCOTT@orcl_11g> SELECT COUNT (*)
  2  FROM   table_title
  3  WHERE  CONTAINS (title, 'BLA') > 0
  4  /

  COUNT(*)
----------
         0

SCOTT@orcl_11g> EXEC DBMS_LOCK.SLEEP (5)

PL/SQL procedure successfully completed.

SCOTT@orcl_11g> SELECT COUNT (*)
  2  FROM   table_title
  3  WHERE  CONTAINS (title, 'BLA') > 0
  4  /

  COUNT(*)
----------
         1

SCOTT@orcl_11g>