Procedure running slow Need inputs for Performance Improovments

Question

we have 3 tables and we need to update the date in one table based on criteria. I had created a procedure and it is taking hours to complete. can any one help me how I can improve the performance.
Here is the procedure
ALTER SESSION SET NLS_DATE_FORMAT = 'DD-MON-YYYY';
DECLARE
   CURSOR c1 is
      select distinct  TO_DATE(po.INTRO_DATE, 'MM/DD/YYYY'), po.article_num,  po.season from  R_INTRO_DATE po where po.band='26' ; 
   introDate Date;
   num1 VARCHAR2(20);
   code VARCHAR2(20);
   sqlquery VARCHAR2(2000);
BEGIN
   OPEN c1;
     FETCH c1 INTO  introDate, num1 , code  ;
    WHILE c1%FOUND loop
     sqlquery := 'update spl  set date2=TO_DATE(''' ||introDate||''', ''DD-MON-YYYY'') where oid=(select distinct spl.oid from spl,seas, sku where seas.att18=''';
    sqlquery := sqlquery ||code ||'''  and sku.att23=''';
    sqlquery := sqlquery ||num1 ||'''  and sku.master=lspl.skuid and seas.master=spl.a3b5)';
      EXECUTE IMMEDIATE (sqlquery);
        FETCH c1 INTO  introDate, num1 , code  ;
   END LOOP;
   CLOSE c1;
END;
Regards
Yadala

Answer 1

Hi Yadala,
Could you please share with the database version you are using?
Do an Explain plan and check if the UPDATE sql use the indexes (if any). Kindly share how many number of records are getting updated as part of this SQL query?
You can try using EXECUTE IMMEDIATE using clause rather hard coding your SQL statements.
http://docs.oracle.com/cd/B13789_01/appdev.101/b10807/13_elems017.htm
https://forums.oracle.com/thread/1067773