some SQL queries taking lot of time.Actually it's a cursor.. which contains select from joining of 2-3 tables and not existalso..
basic form in is::
select count(*) ,... from table1 a table2 b,table3 c
where a.--=b.-- and b.--=c.-- etc
and not exist
(select d, e, f from table d,table e
Basically table also contain around 600000 rows.
Please suggest any option to tune this query to reduce time