Filter in Update (or Transfer) Rules without additional table write

Question

Hi
For filtering out records on a master data attribute in Update Rules (in order to not fill them into Data Target) you can use a start routine like the example blow (from Björn - thanks!)
From the coding I guess that it at least creates and writes into one table.
Is there any way to do this filtering purely in RAM, so the Update Rule just passes on the matching records while simply dropping the filtered records without writing any additional tables than normal during the Update Process?
Full points will be assigned!
Thanks,
German
PROGRAM UPDATE_ROUTINE.
$$ begin of global - insert your declaration only below this line  -
TABLES: ...
TABLES: /BI0/PCUSTOMER.
DATA:   ...
DATA: i_t_customer like /BI0/PCUSTOMER occurs 0 with header line.
$$ end of global - insert your declaration only before this line   -
... internal definitions ...
$$ begin of routine - insert your code only below this line        -
fill the internal tables "MONITOR" and/or "MONITOR_RECNO",
to make monitor entries
  DATA: i_l_data_package LIKE LINE OF DATA_PACKAGE,
          i_t_data_package LIKE STANDARD TABLE OF DATA_PACKAGE.
  select * from /BI0/PCUSTOMER into table i_t_customer.
  LOOP AT DATA_PACKAGE.   
    MOVE-CORRESPONDING DATA_PACKAGE TO i_l_data_package.
    read table i_t_customer with key
      CUSTOMER = i_l_data_package-CUSTOMER.   
    IF sy-subrc = 0.
      IF i_t_customer-COUNTRY = 'DE'.
          APPEND i_l_data_package TO i_t_data_package.
      ENDIF.
    ENDIF.       
  ENDLOOP.
  REFRESH DATA_PACKAGE.
  DATA_PACKAGE[] = i_t_data_package.
  REFRESH i_t_data_package.
if abort is not equal zero, the update process will be canceled
  ABORT = 0.
$$ end of routine - insert your code only before this line         -

Answer 1

Really, if it is your requirement, do the filter in the start routine is less expensive in term of memory consumption and performance.
But I suggest to make a code like this:
select * from /BI0/PCUSTOMER into table i_t_customer.
LOOP AT DATA_PACKAGE.
read table i_t_customer with key
  CUSTOMER = DATA_PACKAGE-CUSTOMER.
IF sy-subrc = 0 and i_t_customer-COUNTRY = 'DE'. 
No Customer with country DE will be in data target!!!!
delete data_package.
ENDIF.
ENDLOOP.
And no other code!
regards,
Sergio