ABAP Code performance

Question

Hi Guys,
The following code seems to be taking considerable time in production. Is there a better way to optimize theis code.
LOOP AT I_T_DATA...
    SELECT SINGLE BUKRS
     INTO (l_bukrs)
     FROM T001K
     WHERE T001K~BWKEY = I_T_DATA-WERKS.
    SELECT SINGLE TARGET1 TARGET2
    INTO (l_salesorg, l_dischan)
    from ZDERIV
    where VALID_FROM le sy-datum
      and SOUR3_FROM le I_T_DATA-prctr
      and SOUR3_TO ge I_T_DATA-prctr
      and SOUR2_FROM le l_bukrs
      and SOUR2_TO ge l_bukrs
      and SOUR1_FROM = 'C100'
      and SOUR1_TO = 'C100'.
    CASE sy-subrc.
     when 0.
       SELECT SINGLE PRODH
       INTO I_T_DATA-zzPRODH
       from mvke
       where matnr eq I_T_DATA-matnr
       and vkorg eq l_salesorg
       and vtweg eq l_dischan.
     WHEN 4.
       Clear: l_salesorg, l_dischan.
    ENDCASE.
Thanks

Answer 1

u don't use select statements in side the loop...cause suppoer ur internal table wch is used for loop has 1000 records..and the table wch is used inside the loop T001w had 500 records..
on the database hitting is  for I_T_DATA is 1000(for example)
                                     1000*500 = 500000... total 1000+500000see hw many times is...for avoid this one u first select the data form db and put into 1 intenal table ...( so it is comes to ur local buffer)..by using this interal table we can use read statement in side the loop...here no data base hitiing...
here the total db hittings : for I_T_DATA: 1000
                                          T001w is      500
                                          Total is      1500.....see the diffrence...
see the code below:
select bukrs into i_too1 for all entries in I_T_DATA where bwkey = I_T_DATA-werks.
SELECT SINGLE TARGET1 TARGET2
INTO table i_ZDERIV----
here it has fields as target1 and target2
from ZDERIV
for all entries in l_i_data
where VALID_FROM le sy-datum
and SOUR3_FROM le I_T_DATA-prctr
and SOUR3_TO ge I_T_DATA-prctr
and SOUR1_FROM = 'C100'
and SOUR1_TO = 'C100'.
after this..
loop at I_T_DATA into wa_t_data.
read table i_t001w into wa_too1w with key bukrs = wa_i_data-werks.
read table i_ZDERIV
into wa_ZDERIV
and SOUR3_FROM le wa_i_DATA-prctr
and SOUR3_TO ge wa_i_DATA-prctr
and SOUR2_FROM le wa_t001w-bukrs
and SOUR2_TO ge wa_t001w-bukrs
with key bukrs = wa_t_data-werks.
here the value of bukrs in wa_t001w-bukrs...
endloop.
inside the loop we can check the sy-subrc's...
i thnk it is useful for u...please give me rely hw it is woking...