Performance on select join vbap/vbak/vbep

Question

Hello,
I would like to know how improve the performance (time-reponse) of my select :
SELECT
apmatkl  approdh apmatnr  aparktx  apvbeln apposnr  apnetwr  apkzwi3  apkzwi1  apmwsbp
epbmeng  epwmeng  epedatu  apvrkme  ap~brgew
INTO CORRESPONDING FIELDS OF TABLE p_tvbapcache
FROM vbap AS ap
INNER JOIN vbep AS ep ON  apvbeln = epvbeln AND apposnr = epposnr
INNER JOIN vbak AS ak ON  akvbeln = epvbeln AND apvbeln = akvbeln
WHERE ak~vbeln NOT LIKE '0005%'
AND ep~vbeln NOT LIKE '0005%'
AND ap~vbeln NOT LIKE '0005%'
AND ep~edatu IN date
AND ap~prodh IN nomencla
AND ak~auart IN canal
AND ap~matnr IN numero
AND apnetwr <> 0 AND apnetwr <> '0'
AND epwmeng <> 0 AND epwmeng <> '0'
AND epbmeng <> 0 AND epbmeng <> '0'
AND apkzwi1 <> 0 AND apkzwi1 <> '0'
AND ak~faksk <> 'Z3'.
The performance are very very very poor...
For information, there are 18.329.040 entries in VBAP table; VBAK : 485.437 entries ; VBEP : 18.304.173 entries
Many thanks for yours ideas,

Answer 1

Hi Coppalle,
Sometimes you need to have a bit more confidence.
Your WHERE-clause checks VBELN for all tables, but in an inner join they are already checked if VBELN is used in the relation.
To check number fields <> 0 <u>AND</u> also <> '0' is not required. Use either one (what you find easy to use), allthough <> 0 is slightly faster.
Since many records are in your tables, consider the following program detail.
DATA: p_tvbapcache_buf LIKE p_tvbapcache OCCURS 0,
      w_tvbapcache_buf LIKE p_tvbapcache.
SELECT ap~vbeln ap~posnr ap~matnr ap~matkl ap~prodh ap~arktx
       ap~netwr ap~kzwi3 ap~kzwi1 ap~mwsbp ap~vrkme ap~brgew
       ep~bmeng ep~wmeng ep~edatu
  INTO CORRESPONDING FIELDS OF TABLE p_tvbapcache_buf
  FROM vbap AS ap PACKAGE SIZE 10000
INNER JOIN vbep AS ep
    ON ap~vbeln = ep~vbeln
   AND ap~posnr = ep~posnr
INNER JOIN vbak AS ak
    ON ak~vbeln = ep~vbeln
   AND ap~vbeln = ak~vbeln
WHERE ak~auart IN canal
   AND ak~faksk <> 'Z3'.
  LOOP AT p_tvbapcache_buf INTO w_tvbapcache_buf.
    CHECK: vbeln NOT LIKE '0005%',
           prodh IN nomencla,
           matnr IN numero,
           netwr <> 0,
           kzwi1 <> 0,
           edatu IN date,
           wmeng <> 0,
           bmeng <> 0.
    APPEND w_tvbapcache_buf TO p_tvbapcache.
  ENDLOOP.
ENDSELECT.
And as last suggestion: I see that you use a lot of 'NEGATIVE' selections (this is selection by exclusion). In the database world this is a very bad way of selecting data, because it will not follow any key in a table. In my opinion you try and find a way of using at least a selection that can use a key.
Hope this gives you some directions,
Regards,
Rob.