Performance problem when creating XML-file

Question

Hi,
I want to create a XML-file with customer data from an internal table. This internal table has appr. 62000 entries. It takes hours to create the elements of the file.
This is the coding I have used:
  loop at it_debtor.
    at first.
    Creating a ixml factory
      l_ixml = cl_ixml=>create( ).
    Creating the dom object model
      l_document = l_ixml->create_document( ).
    Fill root node
      l_element_argdeb  = l_document->create_simple_element(name = 'argDebtors'
                  parent = l_document ).
    endat.
  Create element 'debtor' as child of 'argdeb'
    l_element_debtor  = l_document->create_simple_element(
                 name = 'debtor'
               parent = l_element_argdeb ).
  Create elements as child of 'debtor'
    l_value = it_debtor-admid.
    perform create_element using 'financialAdministrationId'.
    l_value = it_debtor-kunnr.
    perform create_element using 'financialDebtorId'.
    l_value = it_debtor-name1.
    21 child elements in total are created
  endloop.
  Creating a stream factory
  l_streamfactory = l_ixml->create_stream_factory( ).
  Connect internal XML table to stream factory
  l_ostream = l_streamfactory->create_ostream_itable( table =
  l_xml_table ).
  Rendering the document
  l_renderer = l_ixml->create_renderer( ostream  = l_ostream
                                      document = l_document ).
  l_rc = l_renderer->render( ).
  open dataset p_path for output in binary mode.
  if sy-subrc eq 0.
    loop at l_xml_table into rec.
      transfer rec to p_path.
    endloop.
    close dataset p_path.
    if sy-subrc eq 0.
      write:/ wa_lines, 'records have been processed'.
    endif.
  else.
    write:/ p_path, 'can not be opened.'.
  endif.
form create_element using    p_text.
  check not l_value is initial.
  l_element_dummy  = l_document->create_simple_element(
                name = p_text
                value = l_value
                parent = l_element_debtor ).
                                                                                endform.                    " create_element
Please can anyone tell me how to improve the performance.
The method create_simple_element takes a long time.
SAP release : 46C
Regard,
Christine

Answer 1

Hi Christine!
There might be several reasons - but you have to look at the living patient, not only the dead coding.
You did not show any selects, loop at ... where or read table statements -> the usual slow parts are not included (or visible...).
Of course the method-calls can contain slow statements, but you can also have problems because of size (when internal memory gets swaped to disc).
Make a runtime analysis (SE30), have a look in SM50 (details!) for the size, maybe add an info-message for every 1000-customer (-> will be logged in job-log), so you will see if all 1000-packs are executed in same runtime.
With this tools you have to search for the slow parts:
- general out of memory problems, maybe because of to much buffering (visible by slower execution at the end)
- slow methods / selects / other components by SM30 -> have a closer look
Maybe a simple solution: make three portions with 20000 entries each and just copy the files into one, if necessary.
Regards,
Christian