sql quary tunning recommandations

hi all,

please see the below query  and tell me how i tune this sql query below is the tkprof report for this query

sql_query

========

Select

'Dear Customer, we have received the premium of Rs.' ||op.amt ||' against your policy ' || P.Policy_No ||' . Thank you for being a part of XXXXXXXXX.'

From Operations O,

Op_Prem_Payments Op,

Policy P

Where

trunc(sysdate) - trunc(O.Applied_Date) = 10

/* Not in Stop Letter */

And

Not Exists (Select 'X' From Pak_Stp_Ltr Psl Where Psl.Policy_No = P.Policy_No

)

And O.Status Is Null /* Applied Operation */