Hi Jayan
I recommend using FOR ALL ENTRIES in conjunction with DATABASE HINTS.
Additionaly you may have to visit your system parameter settings (please talk to your Basis Consutlant about these).
Please refer to the following Notes for further information -
Note 48230 - Parameterization for SELECT ... FOR ALL ENTRIES statement
Note 634263 - Selects with FOR ALL ENTRIES
Note 130480 - Database hints in Open SQL for Oracle
Note 129385 - Database hints in Open SQL.pdf
Regards
Arijit