Urgent Help Needed - Associating Statistics with User-Defined Functions

Question

Hello,
We have an appication uses cost-based optimizer and uses a lot of TO_DATE and SYSDATE calls in FROM and WHERE clauses. For certain reasons, every call to TO_DATE and SYSDATE has been replaced by MY_TO_DATE and MY_SYSDATE respectively (which in turn call built-in functions). However, cost based optimizer is behaving strangely, which is understanble, based on the lack of user-defined functions statistics. I am under the impression that I should use something like:
ASSOCIATE STATISTICS WITH FUNCTIONS my_to_date DEFAULT SELECTIVITY ?;
ASSOCIATE STATISTICS WITH FUNCTIONS my_to_date COST (?,?,?);
ASSOCIATE STATISTICS WITH FUNCTIONS my_sysdate DEFAULT SELECTIVITY ?;
ASSOCIATE STATISTICS WITH FUNCTIONS my_sysdate COST (?,?,?);
but what should the values (?) be?. I guess I want to replicate TO_DATE and SYSDATE values, but how would I find out what they are? Thanks in advance...
P.S. I am also looking for workarounds (I cannot create a synonym for TO_DATE right?), so any help is welcome!!!

Answer 1

Hi emmalou69 ,
You told your actual parameter is
5, 5, 7.3 and 'z'
so change your method like
public static int test(int x, int y, double d, char ch)
because 5 - int; 7.3- float or double; z is char.
your method returns
public static int.
so you should return only int variable. but in your code you mentioned double. it's not correct.
The original code should look like
public class rubbish
     public static void main(String args[]){
          rubbish f = new rubbish();
          f.test(5, 5, 7.3 ,'z');
     public static int test(int x, int y, double d, char ch)
          int value;
          x = 5;
          y = 5;
          d= 7.3;
          ch = 'z';
          value =((int) d + x + y + ch);
          System.out.println( x + ch + d + y);
          return value;
}//here int value of z is 122.
and int(7.3) is 7
so 7+5+5+122 = 139.3
but value =((int) d + x + y + ch); returns 139. because you convert double to int that is 7.3 to 7
If it is useful, rate me duke dollars,
Thanks