topic Re: binary search question in Application Development and Automation Discussions

binary search question

Former Member — Wed, 25 Jun 2008 14:54:54 GMT

Hi,

I want to use binary search in my code, just not sure, how to do it right.

Let's say I have an IT with columns A B C D.

I want to search this table first based on value in A and later based on B.

How should I sort this table?

>sort IT by A B

>read table with key A = '1' binary search

>read table with key B = 'X' binary search

>sort IT by A

>read table with key A = '1' binary search

>sort IT by B

>read table with key A = 'X' binary search

What happens, if I sort this table by A and let the system search based on value in B?

Thank you,

Olian

Re: binary search question

Former Member — Wed, 25 Jun 2008 14:58:27 GMT

Olien,

prefer SAP help by just pressing F1 in binary search.

may we somtimes wrong but SAP never.

Amit.

Re: binary search question

Former Member — Wed, 25 Jun 2008 15:03:07 GMT

If you are in a loop with these searches you can better make copies of the IT for each sortfield

ITA[] = IT[].

sort ita by A.

read table with key A = '1' binary search

ITB[] = IT[].

sort itb by B.

read table with key B = 'X' binary search.

Re: binary search question

ThomasZloch — Wed, 25 Jun 2008 15:05:44 GMT


>sort IT by A
>read table with key A = '1' binary search
>sort IT by B
>read table with key B = 'X' binary search

That is the way to go (I corrected the typo).

Binary search is only effective when the table is sorted by the search fields. It only makes sense though if you perform multiple reads after sorting (e.g. inside a loop), since sorting itself costs some processing time.

Thomas

Re: binary search question

Former Member — Wed, 25 Jun 2008 15:07:03 GMT

Try in SE30->Tips & Tricks...

Re: binary search question

Former Member — Wed, 25 Jun 2008 15:26:55 GMT

ad you only have to add binary search when the amount of lines in the IT is for instance >10.000

for IT with lines between 0 and 1000 it is not really rewarding.

I had certainly improved some programs in performance with addind binary search to a IT with 30.000 lines which had to be looped through for 5000 times.

kind regards

arthur