How to display tokens generated from submitted document?

Question

Can someone please explain to me the columns located in the DR$<index_name>$I, $K $N $R tables?
What I would like to do is to be able to identify a recently added document and retrieve the tokens generated on that document. I am thinking I can extract this information from the above tables, except I do not understand clearly how they work.

Answer 1

The tokens are stored in dr$<index_name>$i.token_text. The rest of the information is either not of use for your purposes or is not easily accessible in blob columns. Your best bet is to add a date column to your table and populate it automatically with a trigger on insert or update. Then you can extract the tokens for each document and order them by that date column, as demonstrated below. You can limit that selection by date or rownum as you like.
SCOTT@10gXE> CREATE TABLE test_tab
  2    (text_col VARCHAR2 (30),
  3       date_col DATE)
  4  /
Table created.
SCOTT@10gXE> CREATE OR REPLACE TRIGGER test_tab_biur
  2    BEFORE INSERT OR UPDATE ON test_tab
  3    FOR EACH ROW
  4  BEGIN
  5    :NEW.date_col := SYSDATE;
  6  END test_tab_biur;
  7  /
Trigger created.
SCOTT@10gXE> SHOW ERRORS
No errors.
SCOTT@10gXE> INSERT INTO test_tab (text_col) VALUES ('some test data')
  2  /
1 row created.
SCOTT@10gXE> EXEC DBMS_LOCK.SLEEP (5)
PL/SQL procedure successfully completed.
SCOTT@10gXE> INSERT INTO test_tab (text_col) VALUES ('some other test data')
  2  /
1 row created.
SCOTT@10gXE> EXEC DBMS_LOCK.SLEEP (5)
PL/SQL procedure successfully completed.
SCOTT@10gXE> INSERT INTO test_tab (text_col) VALUES ('some more test data')
  2  /
1 row created.
SCOTT@10gXE> CREATE INDEX test_idx ON test_tab (text_col)
  2  INDEXTYPE IS CTXSYS.CONTEXT
  3  /
Index created.
SCOTT@10gXE> COLUMN token_text FORMAT A30
SCOTT@10gXE> BREAK  ON date_col ON text_col SKIP 1
SCOTT@10gXE> SELECT t.date_col, t.text_col, i.token_text
  2  FROM   test_tab t, dr$test_idx$i i
  3  WHERE  CONTAINS (t.text_col, i.token_text) > 0
  4  ORDER  BY t.date_col DESC, t.text_col
  5  /
DATE_COL             TEXT_COL                       TOKEN_TEXT
25-MAY-2006 11:41:02 some more test data            MORE
                                                    TEST
                                                    DATA
25-MAY-2006 11:40:57 some other test data           TEST
                                                    OTHER
                                                    DATA
25-MAY-2006 11:40:52 some test data                 TEST
                                                    DATA
8 rows selected.
SCOTT@10gXE>