Vbrk and Vbrp tables performance problem

Hi all,

The below query is taking lot of time in QAS i need to decrease the time without affecting the logic.....

SELECT vbrk~kunag

vbkd~bstkd

vbkd~bstdk

INTO TABLE c_tab_po FROM vbrp

INNER JOIN vbrk ON vbrk_{mandt = vbrp}mandt AND vbrk~vbeln =

vbrp~vbeln

INNER JOIN vbkd ON vbkd_{mandt = vbrp}mandt AND vbkd~vbeln =

vbrp~aubel

AND vbkd~posnr = con_zposnr

WHERE vbrp~vbeln EQ nast-objky.

DELETE ADJACENT DUPLICATES FROM c_tab_po COMPARING ALL FIELDS.

*Getting the other Invoices based on the customer PO number

IF c_tab_po[] IS NOT INITIAL.

SELECT

vbrk~kunag

vbkd~bstkd

vbkd~bstdk

vbkd_{posex_e vbrk}vkorg

vbrp_{vbeln vbrp}posnr vbrp~erdat

vbpa_{kunnr vbrp}aubel vbrp_{aupos vbak}erdat

vbrp_{matnr vbrk}mwsbk vbrp~netwr

vbrk_{valdt vbrk}zterm vbrk~vbtyp

INTO TABLE g_tab_invoice FROM vbrp

INNER JOIN vbrk ON vbrk_{mandt = vbrp}mandt AND vbrk~vbeln =

vbrp~vbeln

INNER JOIN vbkd ON vbkd_{mandt = vbrp}mandt AND vbkd~vbeln =

vbrp~aubel

AND vbkd~posnr = con_zposnr

INNER JOIN vbpa ON vbpa_{mandt = vbrp}mandt AND vbpa~vbeln =

vbrp~aubel

AND vbpa_{posnr = con_zposnr AND vbpa}parvw =

con_parvw

INNER JOIN vbak ON vbak_{mandt = vbak}mandt AND vbak~vbeln =

vbrp~aubel

FOR ALL entries IN c_tab_po

WHERE vbrk~kunag EQ c_tab_po-kunag AND

vbkd~bstkd EQ c_tab_po-bstkd AND

vbkd~bstdk EQ c_tab_po-bstdk.

ENDIF.