topic Re: Aletrnatives for Nested Loop to same table in Application Development and Automation Discussions

Aletrnatives for Nested Loop to same table

Former Member — Fri, 05 Apr 2013 14:37:35 GMT

Hi,

Is there any alternative for this logic below.....

Table1 consist of date field. Date field in a particular record is checked with all other previous record and then some logic is proccessed.

Normal way is this...

Loop at table1.

l_index = sy-tabix.

Loop at table2(copy of table1) untill l_index.

some logic.

Endloop.

Thanks....

Re: Aletrnatives for Nested Loop to same table

Former Member — Fri, 05 Apr 2013 14:51:58 GMT

Hi Pradosh,

The above code is a good technique when performance is taken into consideration and u can proceed with it. Called Parallel cursor technique and it is an alternative for Nested Loops.

Could u plz tell if u faced any issue with this one ......

Thanks

Vivek

Re: Aletrnatives for Nested Loop to same table

Former Member — Fri, 05 Apr 2013 15:11:26 GMT

hi,

please find exact code as below

data:lv_index type sy-tabix.

Loop at table1.

Loop at table2(copy of table1) from lv_index.

if table1-field <> table2-field

l_index = sy-tabix.

exit.

endif.

some logic.

Endloop.

Re: Aletrnatives for Nested Loop to same table

Former Member — Sat, 06 Apr 2013 05:00:23 GMT

This message was moderated.

Re: Aletrnatives for Nested Loop to same table

Former Member — Sat, 06 Apr 2013 05:05:50 GMT

Hi Krishna,

Thanks for u r concern.........Your approach is correct but my scenario is different.

I need to compare the date field of the table2 with all other previous record's date field of table1

and put into another table(result, I need).

I need alternative other than Nested Loop.....

or else I have to implement this itself...

Regards

Re: Aletrnatives for Nested Loop to same table

former_member189845 — Sat, 06 Apr 2013 05:23:56 GMT

Hi Apta,

This is the More sophisticated loop in which parallel cursors .

For EX:

* Entries: 100 (ITAB1), 1000 (ITAB2)

* Line width: 100

* Both tables sorted by key K

I = 1.

LOOP AT ITAB1 INTO WA1.

LOOP AT ITAB2 INTO WA2 FROM I.

IF WA2-K <> WA1-K.

I = SY-TABIX.

EXIT.

ENDIF.

" ...

ENDLOOP.

this is most efficeint way of coding and measure runtime is only 183 micro seconds.

Thanks,

Siva

Re: Aletrnatives for Nested Loop to same table

uppu_narayan — Sat, 06 Apr 2013 06:22:20 GMT

hi Pradosh,

According to me your requirement doesn't require a parallel cursor technique.......the logic you have written is perfect to your requirement.....

thanks and regards,

narayan

Re: Aletrnatives for Nested Loop to same table

Former Member — Sat, 06 Apr 2013 08:52:33 GMT

Hi Pradosh,

Suppose TABLE2 is copy of TABLE1 and you have 1 additional field in table2 called ZINDEX of TYPE SY-TABIX.

Also assuming that number of data in both internal tables are same (since table2 is reflecting table1):

DATA: ITAB1 TYPE STANDARD TABLE OF TABLE1,

ITAB2 TYPE STANDARD TABLE OF TABLE2,

WA1 TYPE TABLE1,

WA2 TYPE TABLE1.

DATA: INDEX_COUNT TYPE SY-TABIX.

LOOP AT ITAB1 INTO WA1.

INDEX_COUNT = SY-TABIX.

WA2-ZINDEX = INDEX_COUNT.

MODIFY ITAB2 INDEX INDEX_COUNT FROM WA2 TRANSPORTING ZINDEX.

READ TABLE ITAB2 WITH KEY ZINDEX = INDEX_COUNT

IF SY-SUBRC = 0.

perform logic and changes in itab_2

ENDIF.

ENDLOOP.

*******************************

So when SY-TABIX of ITAB1 is 1, changes are made in ITAB2 at index 1, when SY-TABIX of ITAB2 is 2, logic for ITAB2 is executed at index 2 and so on.. And so logic will be applied on each line of ITAB2 till the current index.

(let me know if i am wrong).

Regards,

Khushboo.

Re: Aletrnatives for Nested Loop to same table

Former Member — Sat, 06 Apr 2013 12:41:26 GMT

Thanks for your concern...

You need to understand my requirement....again

Your logic is perfect but it doesn't meet my requirement..

Regards

Re: Aletrnatives for Nested Loop to same table

Former Member — Sat, 06 Apr 2013 12:48:59 GMT

Please Check below link and find your solution

http://wiki.sdn.sap.com/wiki/display/Snippets/ABAP+Code+for+Parallel+Cursor+-+Loop+Processing

Thanks & Regards

RKarmakar