topic Re: Performance of nested loop in Application Development and Automation Discussions

Performance of nested loop

former_member219850 — Tue, 12 May 2015 05:55:01 GMT

I want to improve performance of below code.

Please help..

LOOP AT gt_qmel_qmih INTO gs_qmel_qmih.

lt_jcds[] = lt_jcds_tmp[].

DELETE lt_jcds[] WHERE objnr NE gs_qmel_qmih-objnr.

READ TABLE lt_jcds INTO ls_jcds WITH KEY objnr = gs_qmel_qmih-objnr.

IF sy-subrc EQ 0.

lv_index2 = sy-tabix.

ELSE.

EXIT.

ENDIF.

LOOP AT lt_jcds INTO ls_jcds FROM lv_index2.

IF sy-tabix EQ 1.

gs_tj30t-qmnum = gs_qmel_qmih-qmnum.

gs_tj30t-txt04 = ls_jcds-txt04.

APPEND gs_tj30t TO gt_tj30t.

ENDIF.

CLEAR:gs_tj30t,

ls_jcds,

gs_qmel_qmih.

FREE :gt_jcds.

ENDLOOP.

Re: Performance of nested loop

RaymondGiuseppi — Tue, 12 May 2015 06:03:48 GMT

Well, first rewrite this awful code (and don't panic)


       lt_jcds[] = lt_jcds_tmp[].
       DELETE lt_jcds[] WHERE objnr NE gs_qmel_qmih-objnr.

When there are many notifications loaded, that will kill the performance (n times copy the whole itab and then delete records not required...) better use a sorted/hashed key on objnr and use a simple LOOP WHERE. (which will be optimized to use the key)

Regards,

Raymond

Re: Performance of nested loop

former_member219850 — Tue, 12 May 2015 06:09:36 GMT

Please show sample code.

It will be really helpful...

Thanks,

Darshan.

Re: Performance of nested loop

RaymondGiuseppi — Tue, 12 May 2015 06:14:08 GMT

No code required, just define the table for JCDS data as a TYPE SORTED or HASHED, then use a simple LOOP ON lt_jcds WHERE condition on OBJNR. (reference for performance on LOOP/WHERE)

Regards,

Raymond

Re: Performance of nested loop

matt — Tue, 12 May 2015 06:56:16 GMT

Don't ask for sample code - search and you will find. Read the sap help on tables and indexes. If you want to know about secondary indexes, I wrote a blog about it. You can find that by searching as well.

The more effort you personally put into finding answers, the better you will learn.

Re: Performance of nested loop

Former Member — Tue, 12 May 2015 07:11:43 GMT

Hi Darshan panchal,

Once have a look at this code.

types : r_objnr type range of objnr,

lt_jcds[] = lt_jcds_tmp[].

LOOP AT gt_qmel_qmih INTO gs_qmel_qmih.

r_objnr-sign = 'I'.

r_objnr-option = 'EQ'.

r_objnr-low = gs_qmel_qmih-objnr.

clear r_onjnr.

endloop.

delete lt_jcds[] where objnr not in r_objnr.

LOOP AT gt_qmel_qmih INTO gs_qmel_qmih.

READ TABLE lt_jcds INTO ls_jcds WITH KEY objnr = gs_qmel_qmih-objnr.

IF sy-subrc EQ 0.

lv_index2 = sy-tabix.

ELSE.

EXIT.

ENDIF.

LOOP AT lt_jcds INTO ls_jcds FROM lv_index2.

IF sy-tabix EQ 1.

gs_tj30t-qmnum = gs_qmel_qmih-qmnum.

gs_tj30t-txt04 = ls_jcds-txt04.

APPEND gs_tj30t TO gt_tj30t.

ENDIF.

CLEAR:gs_tj30t,

ls_jcds,

gs_qmel_qmih.

FREE :gt_jcds.

ENDLOOP.

And There is no need of read statement for parallel cursor.Pls try this on your own