Index for "group by" statement.

Question

Hi,
I have a statement directed at the GLPCP table.
It sums op the plan number in each month.
In ABAP it looks like this
SELECT ryear rprctr racct kostl ps_psp_pnr rfarea
         SUM( hsl01 ) SUM( hsl02 ) SUM( hsl03 )
         SUM( hsl04 ) SUM( hsl05 ) SUM( hsl06 )
         SUM( hsl07 ) SUM( hsl08 ) SUM( hsl09 )
         SUM( hsl10 ) SUM( hsl11 ) SUM( hsl12 )
         INTO TABLE e_t_data
         FROM glpcp
         WHERE kokrs   EQ '0020'
         AND   ryear   IN l_r_year
         AND   rldnr   EQ '8A'
         AND   rrcty   EQ '1'
         AND   rvers   EQ '010'
         AND   rbukrs  EQ '0020'
         GROUP BY ryear rprctr racct kostl ps_psp_pnr rfarea.
I have created an index on KOKRS, RYEAR, RLDNR, RRCTY, RVERS, RBUKRS. To support the where statement.
This speeds up the process some but i believe that greater performance can be achieved.
I ran the expression through the SQL explain routine.
The path looks like this http://yfrog.com/jdexplainpathj
It came out with poor performance regarding the group by sentence.
Explanation of query block number: 1   step: 2
Query block type is SELECT
Performance appears to be bad
Method:
.          additional sorts needed
.          for the composite table (current result table)
.          the sorts are performed
.          - to meet an GROUP BY
.          unknown or no prefetch is used
How can i build an index to support the group by sentence.
Best Regards
- Rasmus

Answer 1

Hi Hermann,
I can see why you are confused. It is hard to keep track with the changes.
I will sum up:
The abap statement.
SELECT ryear rprctr racct kostl ps_psp_pnr
         SUM( hsl01 ) SUM( hsl02 ) SUM( hsl03 )
         SUM( hsl04 ) SUM( hsl05 ) SUM( hsl06 )
         SUM( hsl07 ) SUM( hsl08 ) SUM( hsl09 )
         SUM( hsl10 ) SUM( hsl11 ) SUM( hsl12 )
         INTO TABLE it_glpcp
         FROM glpcp
         WHERE kokrs   EQ '0020'
         AND   ryear   IN l_r_year
         AND   rldnr   EQ '8A'
         AND   rrcty   EQ '1'
         AND   rvers   EQ '010'
         AND   rbukrs  EQ '0020'
         GROUP BY rprctr racct kostl ps_psp_pnr ryear.
The SQL statement mad from the abap:
SELECT                                                                               
"RYEAR" , "RPRCTR" , "RACCT" , "KOSTL" , "PS_PSP_PNR" ,"RFAREA" , SUM( "HSL01" ) , SUM( "HSL02" ) ,   
  SUM( "HSL03" ) , SUM("HSL04" ) , SUM( "HSL05" ) , SUM( "HSL06" ) , SUM( "HSL07" ) , SUM("HSL08" ) ,   
  SUM( "HSL09" ) , SUM( "HSL10" ) , SUM( "HSL11" ) , SUM("HSL12" )                                      
FROM                                                                               
"GLPCP"                                                                               
WHERE                                                                               
"RCLNT" = ? AND "KOKRS" = ? AND "RYEAR" =? AND "RLDNR" = ? AND "RRCTY" = ? AND "RVERS" = ? AND "RBUKRS"
  = ?GROUP BY "RYEAR" , "RPRCTR" , "RACCT" , "KOSTL" , "PS_PSP_PNR" ,"RFAREA" FOR FETCH ONLY WITH UR
The index no. 9.
http://yfrog.com/jbidx9j
The hierarchial access path:
http://yfrog.com/1qexplainj
This is where I stand at the moment.
Best Regards,
Rasmus
Edited by: Rasmus Stokholm on Apr 7, 2010 1:13 PM