Performance Issue with BSIS(open accounting items)

Question

Hey All,
      I am having serious performance issue with a accrual report which gets all open GL items, and need some tips for optimization.
The main issue is that I am accesing large tables like BSIS, BSEG, BSAS etc without proper indexes and that I am dealing with huge amounts of data.
The select itself take a long time and after that as I have so much data overall execution is slow too.
The select which concerns me the most is:
  SELECT zuonr hkont gjahr belnr buzei budat blart wrbtr shkzg xblnr waers bukrs
             INTO TABLE i_bsis
              FROM bsis
              WHERE bukrs = '1000'
              AND hkont in r_hkont   
              AND budat <= p_lcdate
              AND augdt = 0
              AND augbl = space
              AND gsber = c_ZRL1   
              AND gjahr BETWEEN l_gjahr2 AND l_gjahr
              AND ( blart = c_re      "Invoice
              OR    blart = c_we      "Goods receipt
              OR    blart = c_zc      "Invoice Cancels
              OR    blart = c_kp ).   "Accounting offset
I have seen other related threads, but was not that helpful.
We already have a secondary index on bukrs hkont and budat, and i have checked in ST05 that it does use it. But inspite that it takes more than 15 hrs to complete(maybe because of huge data).
Any Input is highly appreciated.
Thanks

Answer 1

Thank you Thomas for your inputs:
You said that R_HKONT contains several ranges of account numbers. If these ranges cover a significant
portion of the overall existing account numbers, then there is no really quick access possible via the
BSIS primary key.
Unfortunately R_HKONT contains all account numbers.
As Rob said, your index on HKONT and BUDAT does not help much, since you are selecting "<=" on
BUDAT. No chance of narrowing down that range?
Will look into this.
What about GSBER? Does the value in c_ZRL1 provide a rather small subset of the overall values? Then
an index on BUKRS and GSBER might be helpful.
ZRL1 does provide a decent selection . But I dont know if one more index is a good idea on overall
system performance.
I assume that the four document types are not very selective, so it probably does not pay off to
investigate selecting on BKPF (there is an index involving BLART) and joining BSIS for the additional
information. You still might want to look into it though.
I did try to investigate this option too. Based on other threads related to BSIS and Robs Suggestion in
those threads I tried this:
SELECT bukrs belnr gjahr blart budat
  FROM bkpf INTO TABLE bkpf_l
        WHERE bukrs = c_pepsico
        AND bstat IN (' ', 'A', 'B', 'D', 'M', 'S', 'V', 'W', 'Z')
        AND blart IN ('RE', 'WE', 'ZC', 'KP')
        AND gjahr BETWEEN l_gjahr2 AND l_gjahr
        AND budat <= p_lcdate.
SELECT zuonr hkont gjahr belnr buzei budat blart wrbtr shkzg xblnr waers bukrs
           FROM bsis INTO TABLE i_bsis FOR ALL ENTRIES IN bkpf_l
                     WHERE bukrs = bkpf_l-bukrs
                      AND  hkont IN r_hkont
                      AND  budat = bkpf_l-budat
                      AND  augdt = 0
                      AND  augbl = space
                      AND  gjahr = bkpf_l-gjahr
                      AND  belnr = bkpf_l-belnr
                      AND  blart = bkpf_l-blart
                      AND  gsber = c_zrl1.
The improves the select on BSIS a lot, but the first select on BKPF kills it. Not sure if this would help
improve performance.
Also I was wondering whether it helps on refreshing the tabe statistics through DB20. The last refresh
was done 7 months back. How frequently should we do this? Will it help?