Stored procedure using cursor in mySql.

Question

I wrote a stored procedure using cursor in mysql but that procedure is taking 10 second to fetch the result while that result set have only 450 records so, I want to know that why that proedure is taking that much time to fetch tha record.

procedure as below:

DELIMITER //
DROP PROCEDURE IF EXISTS curdemo123//

CREATE PROCEDURE curdemo123(IN Branchcode int,IN vYear int,IN vMonth int)
   BEGIN
      DECLARE  EndOfData,tempamount INT DEFAULT 0;
      DECLARE tempagent_code,tempplantype,tempsaledate CHAR(12);
      DECLARE tempspot_rate DOUBLE;
      DECLARE var1,totalrow INT DEFAULT 1;
      DECLARE cur1 CURSOR FOR 
              select SQL_CALC_FOUND_ROWS ad.agentCode
                   , ad.planType
                   , ad.amount
                   , ad.date 
                from adplan_detailstbl ad 
               where ad.branchCode=Branchcode 
                 and (    ad.date between '2009-12-1' 
                                      and '2009-12-31')
               order by ad.NUM_ID asc;
      DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET EndOfData = 1;
      DROP TEMPORARY TABLE IF EXISTS temptable;

      CREATE TEMPORARY TABLE temptable (
             agent_code varchar(15)
           , plan_type char(12)
           , sale double
           , spot_rate double default '0.0', dATE DATE
      );

      OPEN cur1;
      SET totalrow=FOUND_ROWS();
      while var1 <= totalrow DO
         fetch cur1 into tempagent_code
                        ,tempplantype
                        ,tempamount
                        ,tempsaledate;

         IF( (    tempplantype='Unit Plan' 
               OR tempplantype='MIP'
             ) OR tempplantype='STUP') THEN

            select spotRate into tempspot_rate 
              from spot_amount 
              where ((    monthCode=vMonth 
                      and year=vYear) 
                    and (     (     agentCode=tempagent_code 
                                and branchCode=Branchcode) 
                          and (planType=tempplantype)
              ));

            INSERT INTO temptable VALUES(
                tempagent_code
               ,tempplantype
               ,tempamount
               ,tempspot_rate
               ,tempsaledate)
           ;
      else
         INSERT INTO temptable(
              agent_code
             ,plan_type
             ,sale,dATE) 
         VALUES( tempagent_code,tempplantype,tempamount,tempsaledate);
      END IF;

      SET var1=var1+1;
END WHILE;
CLOSE cur1;
select * from temptable;
DROP TABLE  temptable;
END //
DELIMITER ;

Answer 1

It's the nature of cursors to be slow, there's nothing in your code that is obviously bad designed. Remember that for each of your 450 rows your curosr iterates over you are issuing one or two statements. Each of those queries will be run on it's own. Issuing 450-900 Statements like this on their own would probably take similar time.

That's why you should, whenever possible, try to avoid cursors.

It looks like you want to, depending on a certain criteria, select one set ov values or another. Maybe you split up your query into two select queries (for each case of the criteria) and UNION the result.

Answer 2

please run the following and paste ALL the results into http://pastie.org/ you should replace the ?? in the select statements with proper test values before executing

 show table status like 'adplan_detailstbl'\G
 show create table adplan_detailstbl \G
 show indexes from adplan_detailstbl;

 explain select 
  ad.* 
 from 
  adplan_detailstbl ad 
 where 
  ad.branchCode = ?? and ad.date between '2009-12-01' and '2009-12-31'
 order by 
  ad.NUM_ID;

 show table status like 'spot_amount'\G
 show create table spot_amount \G
 show indexes from spot_amount;

 explain select * from 
  spot_amount
 where 
  monthCode=?? and year=?? and agentCode=?? and branchCode=?? and planType=??;