Tips by: Horacio Zapettini

report zuseofhashedtables.
************************************************************************
** Program: ZUseOfHashedTables                                        **
************************************************************************
** Author: Horacio Zapettini                                          **
**                                                                    **
** Versions: 4.6b - 4.6c                                              **
************************************************************************
** Notes:                                                             **
**     this program shows how we can use hashed tables to improve     **
**     the responce time.                                             **
**     It shows,                                                      **
**        1. how to declare hashed tables                             **
**        2. a cache-like technique to improve access to master data  **
**        3. how to collect data using hashed tables                  **
**        4. how to avoid deletions of unwanted data                  **
************************************************************************
** Results: the test we run read about 31000 rows from mkpf, 150000   **
**          rows from mseg, 500 rows from makt and 400 from lfa1.     **
**          it filled ht_lst with 24500 rows and displayed them in    **
**          alv grid format.                                          **
**                                                                    **
**          It needed about 65 seconds to perform this task (with     **
**          all the db buffers empty)                                 **
**                                                                    **
**          The same program with standard tables needed 140 seconds  **
**          to run with the same recordset and with buffers filled in **
************************************************************************
** Objetive: show a list that consists of  all the material movements **
**          '101' - '901' for a certain range of dates in mkpf-budat. **
** the columns to be displayed are:                                   **
**          mkpf-budat,                                               **
**          mkpf-mblnr,                                               **
**          mseg-lifnr,                                               **
**          lfa1-name1,                                               **
**          mkpf-xblnr,                                               **
**          mseg-zeile                                                **
**          mseg-charg,                                               **
**          mseg-matnr,                                               **
**          makt-maktx,                                               **
**          mseg-erfmg,                                               **
**          mseg-erfme.                                               **
** or show a sumary list by matnr - menge                             **
**                                                                    **
** You'll have to create a pf-status called vista -                   **
** See form set_pf_status for details                                 **
************************************************************************

** tables used -
tables: mkpf,
        mseg,
        lfa1,
        makt.

** global hashed tables used
*
data: begin of wa_mkpf, "header
      mblnr like mkpf-mblnr,
      mjahr like mkpf-mjahr,
      budat like mkpf-budat,
      xblnr like mkpf-xblnr,
      end of wa_mkpf.
data: ht_mkpf like hashed table of wa_mkpf
      with unique key mblnr mjahr
      with header line.
*
data: begin of wa_mseg, " line items
      mblnr like mseg-mblnr,
      mjahr like mseg-mjahr,
      zeile like mseg-zeile,
      bwart like mseg-bwart,
      charg like mseg-charg,
      matnr like mseg-matnr,
      lifnr like mseg-lifnr,
      erfmg like mseg-erfmg,
      erfme like mseg-erfme,
      end of wa_mseg.
data ht_mseg like hashed table of wa_mseg
      with unique key mblnr mjahr zeile
      with header line.

** cache structure for lfa1 records
data: begin of wa_lfa1,
      lifnr like lfa1-lifnr,
      name1 like lfa1-name1,
      end of wa_lfa1.
data ht_lfa1 like hashed table of wa_lfa1
      with unique key lifnr
      with header line.

** cache structure for material related data
data: begin of wa_material,
      matnr like makt-matnr,
      maktx like makt-maktx,
      end of wa_material.
data: ht_material like hashed table of wa_material
        with unique key matnr
        with header line.

** result table
data: begin of wa_lst, "
      budat like mkpf-budat,
      mblnr like mseg-mblnr,
      lifnr like mseg-lifnr,
      name1 like lfa1-name1,    
      xblnr like mkpf-xblnr,
      zeile like mseg-zeile,
      charg like mseg-charg,
      matnr like mseg-matnr,
      maktx like makt-maktx,
      erfmg like mseg-erfmg,
      erfme like mseg-erfme,
      mjahr like mseg-mjahr,
      end of wa_lst.

data: ht_lst like hashed table of wa_lst
        with unique key mblnr mjahr zeile
        with header line.

data: begin of wa_lst1, " sumary by material
      matnr like mseg-matnr,
      maktx like makt-maktx,
      erfmg like mseg-erfmg,
      erfme like mseg-erfme,
      end of wa_lst1.

data: ht_lst1 like hashed table of wa_lst1
        with unique key matnr
        with header line.

** structures for alv grid display.
** itabs
type-pools: slis.

data: it_lst            like standard table of wa_lst with header line,
      it_fieldcat_lst   type slis_t_fieldcat_alv with header line,
      it_sort_lst       type slis_t_sortinfo_alv,
      it_lst1           like standard table of wa_lst1 with header line,
      it_fieldcat_lst1  type slis_t_fieldcat_alv with header line,
      it_sort_lst1      type slis_t_sortinfo_alv.
** structures
data: wa_sort         type slis_sortinfo_alv,
      ls_layout       type slis_layout_alv.

** global varialbes

data: g_lines type i.

data: g_repid like sy-repid,
      ok_code       like sy-ucomm.

** selection-screen

"text: Dates:
select-options: so_budat for mkpf-budat default sy-datum.
"text: Material numbers.
select-options: so_matnr for mseg-matnr.
selection-screen uline.
selection-screen skip 1.
"Text: show summary by material.
parameters: gp_bymat as checkbox default ''.

start-of-selection.
  perform get_data.
  perform show_data.

end-of-selection.


*---------------------------------------------------------------------*
*       FORM get_data                                                 *
*---------------------------------------------------------------------*
*       ........                                                      *
*---------------------------------------------------------------------*
form get_data.
        select mblnr mjahr budat xblnr
            into table ht_mkpf
           from mkpf
          where budat in so_budat. " make use of std index.
** have we retrieved data from mkpf?
  describe table ht_mkpf lines g_lines.
  if g_lines > 0.
** if true then retrieve all related records from mseg.
** Doing this way we make sure that the access is by primary key
** of mseg.
** The reason is that is faster to filter them in memory
** than to allow the db server to do it.
    select mblnr mjahr zeile bwart charg
             matnr lifnr erfmg erfme
      into table ht_mseg
      from mseg
        for all entries in ht_mkpf
     where mblnr = ht_mkpf-mblnr
       and mjahr = ht_mkpf-mjahr.
  endif.
        
** fill t_lst or t_lst1 according to user's choice.
  if gp_bymat = ' '.
    perform fill_ht_lst.
  else.
    perform fill_ht_lst1.
  endif.
endform.

form fill_ht_lst.
  refresh ht_lst.
** Example: how to discard unwanted data in an efficient way.
  loop at ht_mseg.
*   filter unwanted data
    check ht_mseg-bwart = '101' or ht_mseg-bwart = '901'.
    check ht_mseg-matnr in so_matnr.
*   read header line.
    read table ht_mkpf with table key mblnr = ht_mseg-mblnr
    mjahr = ht_mseg-mjahr.
    clear ht_lst.
*  * note : this may be faster if you specify field by field.
    move-corresponding ht_mkpf to ht_lst.
    move-corresponding ht_mseg to ht_lst.

    perform read_lfa1 using ht_mseg-lifnr changing ht_lst-name1.
    perform read_material using ht_mseg-matnr changing ht_lst-maktx.
    insert table ht_lst.
  endloop.
endform.

form fill_ht_lst1.
  refresh ht_lst1.
** Example: how to discard unwanted data in an efficient way.
**          hot to simulate a collect in a faster way
  loop at ht_mseg.
*   filter unwanted data
    check ht_mseg-bwart = '101' or ht_mseg-bwart = '901'.
    check ht_mseg-matnr in so_matnr.
*  * note : this may be faster if you specify field by field.

    read table ht_lst1 with table key matnr = ht_mseg-matnr
    transporting erfmg.
    if sy-subrc <> 0. " if matnr doesn't exist in sumary table
    " insert a new record
      ht_lst1-matnr = ht_mseg-matnr.
      perform read_material using ht_mseg-matnr changing ht_lst1-maktx.
      ht_lst1-erfmg = ht_mseg-erfmg.
      ht_lst1-erfme = ht_mseg-erfme.
      insert table ht_lst1.
    else." a record was found.
    " collect erfmg.  To do so, fill in the unique key and add
    " the numeric fields.
      ht_lst1-matnr = ht_mseg-matnr.
      add ht_mseg-erfmg to ht_lst1-erfmg.
      modify table ht_lst1 transporting erfmg.
    endif.
  endloop.
endform.

** implementation of cache for lfa1.
form read_lfa1 using p_lifnr changing p_name1.
        read table ht_lfa1 with table key lifnr = p_lifnr
        transporting name1.
  if sy-subrc <> 0.
    clear ht_lfa1.
    ht_lfa1-lifnr = p_lifnr.
    select single name1
       into ht_lfa1-name1
      from lfa1
    where lifnr = p_lifnr.
    if sy-subrc <> 0. ht_lfa1-name1 = 'n/a in lfa1'. endif.
    insert table ht_lfa1.
  endif.
  p_name1 = ht_lfa1-name1.
endform.

** implementation of cache for material data
form read_material using p_matnr changing p_maktx.
  read table ht_material with table key matnr = p_matnr
  transporting maktx.
  if sy-subrc <> 0.
    ht_material-matnr = p_matnr.
    select single maktx into  ht_material-maktx
      from makt
     where spras = sy-langu
       and matnr = p_matnr.
    if sy-subrc <> 0. ht_material-maktx = 'n/a in makt'. endif.
    insert table ht_material.
  endif.
  p_maktx = ht_material-maktx.
endform.
form show_data.
  if gp_bymat = ' '.
    perform show_ht_lst.
  else.
    perform show_ht_lst1.
  endif.
endform.
form show_ht_lst.
  "needed because the FM can't use a hashed table.
  it_lst[] = ht_lst[].

  perform fill_layout using 'full display'
                       changing ls_layout.

  perform fill_columns_lst.
*  perform sort_lst.
  g_repid = sy-repid.
  call function 'REUSE_ALV_GRID_DISPLAY'
       exporting
            i_callback_program       = g_repid
            i_callback_pf_status_set = 'SET_PF_STATUS'
            is_layout                = ls_layout
            it_fieldcat              = it_fieldcat_lst[]
*            it_sort                  = it_sort_lst
       tables
            t_outtab                 = it_lst
       exceptions
            program_error            = 1
            others                   = 2.

endform.
form show_ht_lst1.
  "needed because the FM can't use a hashed table.
  it_lst1[] = ht_lst1[].

  perform fill_layout using 'Sumary by matnr'
                       changing ls_layout.

  perform fill_columns_lst1.
*  perform sort_lst.
  g_repid = sy-repid.
  call function 'REUSE_ALV_GRID_DISPLAY'
       exporting
            i_callback_program       = g_repid
            i_callback_pf_status_set = 'SET_PF_STATUS'
            is_layout                = ls_layout
            it_fieldcat              = it_fieldcat_lst1[]
*            it_sort                  = it_sort_lst
       tables
            t_outtab                 = it_lst1
       exceptions
            program_error            = 1
            others                   = 2.

endform.

form fill_layout using p_window_titlebar
               changing cs_layo type slis_layout_alv.
  clear cs_layo.
  cs_layo-window_titlebar        = p_window_titlebar.
  cs_layo-edit                   = 'X'.
  cs_layo-edit_mode              = space.
endform.                    " armar_layout_stock

form set_pf_status using rt_extab type slis_t_extab.
** create a new status
** and then select extras -> adjust template -> listviewer
  set pf-status 'VISTA'.
endform.        "set_pf_status
define add_lst.
  clear it_fieldcat_lst.
  it_fieldcat_lst-fieldname     = &1.
  it_fieldcat_lst-outputlen     = &2.
  it_fieldcat_lst-ddictxt       = 'L'.
  it_fieldcat_lst-seltext_l       = &1.
  it_fieldcat_lst-seltext_m       = &1.
  it_fieldcat_lst-seltext_m       = &1.
  if &1 = 'MATNR'.
    it_fieldcat_lst-emphasize = 'C111'.
  endif.
  append it_fieldcat_lst.
end-of-definition.
define add_lst1.
  clear it_fieldcat_lst.
  it_fieldcat_lst1-fieldname     = &1.
  it_fieldcat_lst1-outputlen     = &2.
  it_fieldcat_lst1-ddictxt       = 'L'.
  it_fieldcat_lst1-seltext_l       = &1.
  it_fieldcat_lst1-seltext_m       = &1.
  it_fieldcat_lst1-seltext_m       = &1.
  append it_fieldcat_lst1.
end-of-definition.

form fill_columns_lst.
* set columns for output.

  refresh it_fieldcat_lst.
*
  add_lst 'BUDAT' 10.
  add_lst   'MBLNR' 10.
  add_lst  'LIFNR' 10.
  add_lst  'NAME1' 35.
  add_lst  'XBLNR' 15.
  add_lst    'ZEILE' 5.
  add_lst    'CHARG' 10.
  add_lst   'MATNR' 18.
  add_lst   'MAKTX' 30.
  add_lst   'ERFMG' 17.
  add_lst   'ERFME' 5.
  add_lst   'MJAHR' 4.
endform.
form fill_columns_lst1.
* set columns for output.

  refresh it_fieldcat_lst1.

  add_lst1 'MATNR' 18.
  add_lst1 'MAKTX' 30.
  add_lst1 'ERFMG' 17.
  add_lst1 'ERFME' 5..
endform.

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