Select statement using BSEG table

Question

Hello SAPinas,
I am using the following lines of code in one of my program. Becuase of that code I am getting Performance issue.
Note : BSEG is Cluster Table.
Could you please help me how I will use in another way
loop at t_hdr.
    select buzei buzid koart shkzg mwskz dmbtr hwbas sgtxt vbund kostl
           aufnr anln1 anln2 hkont kunnr lifnr matnr werks ebeln ebelp
           zekkn rewrt prctr txjcd projk
    into (t_item-buzei, t_item-buzid, t_item-koart, t_item-shkzg,
          t_item-mwskz, t_item-dmbtr, t_item-hwbas, t_item-sgtxt,
          t_item-vbund, t_item-kostl, t_item-aufnr, t_item-anln1,
          t_item-anln2, t_item-hkont, t_item-kunnr, t_item-lifnr,
          t_item-matnr, t_item-werks, t_item-ebeln, t_item-ebelp,
          t_item-zekkn, t_item-rewrt, t_item-prctr, t_item-txjcd,
          t_item-projk)
    from bseg
   where bukrs  = t_hdr-bukrs
     and belnr  = t_hdr-belnr
     and gjahr  = t_hdr-gjahr
     and hkont in s_hkont
     and mwskz in s_mwskz
     and kostl in s_kostl
     and prctr in s_prctr
     and werks in s_werks.
Skip record if not in selection screen range for state
      check t_item-txjcd(2) in s_state.
      if t_item-shkzg  = c_debit.  "S
      endif.
      if t_item-shkzg  = c_credit. "H
        t_item-dmbtr = t_item-dmbtr * ( -1 ).
        t_item-rewrt = t_item-rewrt * ( -1 ).
        t_item-hwbas = t_item-hwbas * ( -1 ).
      endif.
**&MWB 04/08/2005 ... add additional US Bayer Tax dept requested fields
      clear: t_item-basetax, t_item-accrtax, t_item-vendtax,
             t_item-taxrate, t_item-invbase, t_item-invtax.
**&MWB ... end insert 04/08/2005
      clear t_item-hwbas.
      move-corresponding t_hdr to t_item.
      append t_item.
      clear  t_item.
    endselect.
  endloop.
Thank you very much Advance.............:-)

Answer 1

As BSEG is in a cluster table RFBLG, the only index available is the primary one, so only BUKRS, BELNR and GJAHR keys are actually available. So for other criteria resolution, the program will read the whole cluster, unpacking the records and executing the selection. When most criteria come from BKPF header, you may select from BKPF and then from BSEG using the full key of the cluster, and using a [FOR ALL ENTRIES|http://help.sap.com/abapdocu/en/ABENOPEN_SQL_PERFO.htm] IN a table with the keys from BKPF.
Try to use one or more of the secondary indexes provide by SAP
- BSAD Accounting: Secondary Index for Customers (Cleared Items)
- BSAK Accounting: Secondary Index for Vendors (Cleared Items)
- BSAS Accounting: Secondary Index for G/L Accounts (Cleared Items)
- BSID Accounting: Secondary Index for Customers
- BSIK Accounting: Secondary Index for Vendors
- BSIM Secondary Index, Documents for Material
- BSIS Accounting: Secondary Index for G/L Accounts
These indexes are actual tables, so you may create/use indexes, they are also easily appended, as they are filled via move-corresponding statements.
Try a little search at sdn on keywords like [BSEG, cluster and performance|https://www.sdn.sap.com/irj/scn/advancedsearch?cat=sdn_all&query=bsegclusterperformance&adv=false&sortby=cm_rnd_rankvalue].
Regards