11-27-2014 9:40 AM
Hi Experts,
Need some advice!!!
We have a 2 select query on VICDCOND which should use index 6&9( provided by SAP), however they are not being used in select statement. Instead the DB goes for FULL TABLE SCAN.
Query 1
SELECT intreno FROM vicdcond APPENDING TABLE lt_intreno
WHERE objnrdistpara = id_objnr AND
conddelete = abap_false.
Query 2
SELECT intreno objnr FROM vicdcond
INTO TABLE lt_cond_int
FOR ALL ENTRIES IN lt_hier
WHERE calcrule = lt_hier-calcruleext.
The above query goes for full table scan even though index exist for CALCRULE(Index 9) and for objnrdistpara & conddelete(Index 6).
We even for DB stats updated but even that didn't change the result. Please share your thought on next course of action.
Is anyone aware of performance issues related to REFX or table VICDCOND or any other SAP Notes that might help.
PS : Both the queries are part of standard code.
Thanks,
Chirantan
12-01-2014 2:50 PM
Hi Chiratan,
if this is part of standard program, I think you should 1st check SAPNET OSS notes.
Maybe some notes correcting this already exist.
Try to search with VCDCOND + Performance or the standard program name + performance.
If the index are not used even after stats were calculated again, then it means maybe that the stats of the table+index lead the DB to that choice.
So for example if the index 9 has very few disctinct values, and this table is big, then maybe DB will go to a full scan instead to use an index which seems not efficient for it.
So maybe check the stats of the table & index .
And check if really these index will be better than full scans.
Also.
I dont know this table size on your systems. But "full scan" is not equal to "bad" .
Did you notice that these full scans are long ? Or just trying to avoid full scans ? (because we all always read that "full scan" is bad).
How much time is spend on these SELECTs ?
S.N
12-01-2014 3:04 PM
There are performance notes for RE-FX and related BW extractors until 2014, so perform an OSS note for your system level.
NB: I agree with the Newbie” , for standard program performance, always start with an OSS search.
Regards,
Raymond