topic Re: Join conditions in Application Development and Automation Discussions

Join conditions

Former Member — Fri, 15 Jun 2007 13:34:52 GMT

Hi ,

i have a small questions.

will join conditions in sql queries affect perfomance? how? give with an example

Re: Join conditions

Former Member — Fri, 15 Jun 2007 13:40:20 GMT

Hi,

Look at the below link, you will get the correct information

http://blogs.ittoolbox.com/sap/db2/archives/for-all-entries-vs-db2-join-8912

Regards

Sudheer

Re: Join conditions

Former Member — Fri, 15 Jun 2007 13:41:17 GMT

hi raju,

join's will affect the performance,

instead of this u can use for all entries.

reward points if helpful,

regards,

seshu.

Re: Join conditions

Former Member — Fri, 15 Jun 2007 13:43:29 GMT

Hello,

Join  -  Used when the data in the table is less.

For all entries - Used when the data in the table is huge.

So use like this.

Vasanth

Re: Join conditions

Former Member — Fri, 15 Jun 2007 13:47:52 GMT

hi,

deffinetly it will affects the perfomace.

it will improves the perfomance when using view insted of using multiple select statements.

When multiple SAP tables are logically joined, it is always advisable to use inner join to read the data from them. This certainly reduces the load on the network.

but we can improve the perfomance by using FOR ALL ENTRIES insted of using VIEWS .

regards,

Ashokreddy.

Re: Join conditions

Former Member — Fri, 15 Jun 2007 13:48:09 GMT

check this:

<a href="/people/rob.burbank/blog/2007/03/19/joins-vs-for-all-entries--which-performs-better">JOINS vs. FOR ALL ENTRIES - Which Performs Better?</a>

Rob

Re: Join conditions

Former Member — Fri, 15 Jun 2007 14:12:11 GMT

Join will definetly affect ur performance.. Instead of this use For all entries.

Procedure.

Select all fields from one table and put it into one internal table.

then select fields from 2nd table using for all entries and put into another table.

This will reduce ur performance.

Reward me if its useful

Regards

Ravi

Re: Join conditions

Former Member — Fri, 22 Jun 2007 10:42:50 GMT

Hi Vasanth,

You may have said the answer. But how will you know when you are writing a report whether it has large or small amount of data while writing a program for implementation Project. We will not all have any data for checking the performance. Ok . tell me something other than this if you know.

Re: Join conditions

Former Member — Fri, 22 Jun 2007 13:23:06 GMT

The short answer is that it doesn't matter that much. Either method will give adequate performace. It's far more important to make sure you are using an index properly.

Rob

Re: Join conditions

Former Member — Thu, 21 Jul 2011 07:58:42 GMT

answered