SYS_REFCURSOR, open cursor

Question

I have a function that is returning an address.
CREATE OR REPLACE FUNCTION GetAnyRows_01(p_paid IN NUMBER)
RETURN SYS_REFCURSOR
AS
   rc SYS_REFCURSOR;
BEGIN
     OPEN rc FOR SELECT ans_strasse_pf, ans_plz, ans_ort
                FROM anschriften
                where ans_pa_pa_id = p_paid;
    RETURN rc;
END;
/The third column of my select statement contains the function, which is returning a ref
cursor construct.
SQL> select pa_pa_id Nr#,
  2         pa_geschlecht mw, 
  3         GetAnyRows_01(pa_pa_id) address
  4  from partners
  5  where pa_pa_id in (20,46)
  6  order by 1
  7  /
       NR# M ADDRESS
        20 m CURSOR STATEMENT : 3
CURSOR STATEMENT : 3
ANS_STRASSE_PF                           ANS_P ANS_ORT
Peterstreet 46                           20566 Hamburg
        46 m CURSOR STATEMENT : 3
CURSOR STATEMENT : 3
ANS_STRASSE_PF                           ANS_P ANS_ORT
Dragon Heart 1                           97745 Munich
SQL> First if want to know, if this okay, programming a SYS_REFCURSOR for solving this problem?
What do you think about it?
~
With the following statement I must get at about 16.000 rows, but I get an error :-(
SQL> select pa_pa_id Nr#,
  2         pa_geschlecht mw, 
  3         GetAnyRows_01(pa_pa_id) address
  4  from partners
  5  --where pa_pa_id in (20,46)
  6  order by 1
  7  /
       GetAnyRows_01(pa_pa_id) address
FEHLER in Zeile 3:
ORA-01000: maximum open cursors exceeded
ORA-06512: in "MAD.GETANYROWS_01", Line 14
SQL> I have checked the open cursor of my session:
SQL> SELECT o.sid, s.username, substr(machine,1,32), count(*)
  2  FROM v$open_cursor o, v$session s
  3  WHERE o.sid = s.sid
  4  GROUP BY o.sid, s.username, machine
  5  HAVING COUNT(*) > 1
  6  ORDER BY count(*) desc;
       SID USERNAME                       SUBSTR(MACHINE,1,32)               COUNT(*)
       146 MAD                            bello                                   557Does anybody have an idea?

Answer 1

I have checked the open cursor of my session:
SQL> SELECT o.sid, s.username, substr(machine,1,32),
count(*)
2  FROM v$open_cursor o, v$session s
3  WHERE o.sid = s.sid
4  GROUP BY o.sid, s.username, machine
5  HAVING COUNT(*) > 1
6  ORDER BY count(*) desc;
SID USERNAME
SUBSTR(MACHINE,1,32)
COUNT(*)
146 MAD                            bello
557This proves nothing as the cursors may have been closed after the SQL finished.
The problem is that for each row of data you are opening a ref cursor, but these opened cursors are not being closed for each row.
Can you not just join to the address table that is in the function and retrieve the data as an additional column? It doesn't really seem like you need to use a function in this case.
Also bear in mind that calling user defined functions from within SQL causes a performance issue when dealing with lots of rows of data due to the context switching between SQL and PL/SQL that has to take place.
If you can do it just in SQL then do that. Ony resort to PL/SQL when absolutely necessary.