PO value , PO quantity, GR value and GR quantity

Hi all,

I need to find PO value , PO quantity, GR value and GR quantity.

i have used the following tables: EKKO, EKPO, MSEG and i got the required report.

but my problem here is performance issue.

i am getting data from MSEG using fields EBELN, EBELP which are not key fields....here key fields are

MBLNR

MJAHR

ZEILE   ...but i am not using these fields to get the data.....even i didnt find any way to use these fields.....

so my report is lack of performance.....

can anyone give me suggestion to use the key fields of MSEG table.....

thanks..

surya