How to create hashed table in runtime

Question

hi experts
how to create hashed table in runtime, please give me the coading style.
please help me.
regards
subhasis

Answer 1

Hi,
Have alook at the code, and pls reward points.
Use Hashed Tables to Improve Performance :
report zuseofhashedtables.
Program: ZUseOfHashedTables                                        **
Author: XXXXXXXXXXXXXXXXXX                                 **
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.
Regards,
Ameet