I am facing performance issue in a report due to addition of occurs clause

Question

Hi,
I am facing performance in one program. I think while declaring internal table used OCCURS 100 but records are populating 470840 no of records.
again in 2nd internal table declared OCCURS 10 but records are entering 18 no of records.
I guess because of this program is taking nearly 30 mins time and not getting correct out put.
I am not sure weather this is the reason.
So any one can give proper suggestion to improve the performance of the program
in the internal table t_dels_tvpod  showing the no of records in debugging = 470840 * 9(80)
in the internal table lt_dels_tvpod  showing the no of records in debugging = 18 * 9(80)
I have shown the part of the program code.
Program code
DATA:   BEGIN OF t_dels_tvpod OCCURS 100,
          vbeln LIKE tvpod-vbeln,     
          posnr LIKE tvpod-posnr,     
          lfimg_diff LIKE tvpod-lfimg_diff,
          calcu LIKE tvpod-calcu,
          podmg LIKE tvpod-podmg,
          uecha LIKE lips-uecha,      
          pstyv LIKE lips-pstyv,      
          xchar LIKE lips-xchar,      
          grund LIKE tvpod-grund,                          
        END OF t_dels_tvpod,
DATA: l_tabix LIKE sy-tabix,
        lt_dels_tvpod LIKE t_dels_tvpod OCCURS 10 WITH HEADER LINE,
        ls_dels_tvpod LIKE t_dels_tvpod.
SELECT vbeln INTO TABLE lt_dels_tvpod FROM likp
         FOR ALL ENTRIES IN t_dels_tvpod
         WHERE vbeln = t_dels_tvpod-vbeln
         AND   erdat IN s_erdat
         AND   bldat IN s_bldat
         AND   podat IN s_podat
         AND   ernam IN s_ernam
         AND   kunnr IN s_kunnr
         AND   vkorg IN s_vkorg
         AND   vstel IN s_vstel
         AND   lfart NOT IN r_del_types_exclude.
Waiting for quick response.
Best regards,
BDP

Answer 1

You should declare your structure with TYPES statement and with  this type declare internal table.
Example:
types: begin of ty_itb,
           budat type budat,
           matnr type matnr,
           end of ty_itab.
data: itab type standard table of ty_itb,
        wa_itab like line of itab.  (work area of itab)
Since both occurs and header line statements are obsolete.
change the below select query as follows can improve the performence
if not IN t_dels_tvpod[] is initial. (always check this, if you are using For all entries statement)
SELECT vbeln lfart INTO TABLE lt_dels_tvpod FROM likp
FOR ALL ENTRIES IN t_dels_tvpod
WHERE vbeln = t_dels_tvpod-vbeln
AND erdat IN s_erdat
AND bldat IN s_bldat
AND podat IN s_podat
AND ernam IN s_ernam
AND kunnr IN s_kunnr
AND vkorg IN s_vkorg
AND vstel IN s_vstel.
endif.
delete  lt_dels_tvpod where lfart not in r_del_types_exclude.