topic Re: I need help in Application Development and Automation Discussions

I need help

Former Member — Thu, 29 Mar 2007 07:31:57 GMT

Hi friends,

what is the main difference between the Innejoin and For all Entries

Performance wise which one is the best

Please Help me.

Regards,

Srilavi

Re: I need help

Former Member — Thu, 29 Mar 2007 07:37:05 GMT

Check these links:

Re: I need help

Former Member — Thu, 29 Mar 2007 07:37:40 GMT

Hi Srilavi,

Click here: /people/rob.burbank/blog/2007/03/19/joins-vs-for-all-entries--which-performs-better .

You will get to know complete details about JOINS vs FOR ALL ENTRIES.

Hope you will understand clearly about these JOINS vs FOR ALL ENTRIES.

Reward if helpful

Regards,

V.Raghavender.

Re: I need help

Former Member — Thu, 29 Mar 2007 07:41:49 GMT

hi,

INNER JOINs gives the intersection of the tables that meet the WHERE clause.

FOR ALL ENTRIES eliminates duplicates from the results that meet the WHERE clause.

regards,

ananth

Re: I need help

former_member673464 — Thu, 29 Mar 2007 07:43:58 GMT

hi,

Inner join is used to retrive data from data base using specific condition in single internal table where as in for all entries you retrieve data into two different internal tables.You need to again merge two tables to get the required information.

regards,

veeresh

Re: I need help

Former Member — Thu, 29 Mar 2007 07:44:23 GMT

Hi!

INNER JOIN is used if we want to retrieve some data from more than one table.

FOR ALL ENTRIES is used if we want some data from a table based on some conditions of some other table.

Using several nested INNER JOIN statements can be inefficient and cause time out if the tables become too big in the future."

In ABAP, these joins are first split by the ABAP processor and then sent to the database, with the increase in DATA in production system, these joins tend to give way if your database keeps growing larger and larger.

You should rather use "FOR ALL ENTRIES IN" (Tabular conditions), which is a much efficient way as far as performance is concerned.

Reward points if it helps.

Regards,

Neha Bansal.

Re: I need help

Former Member — Thu, 29 Mar 2007 07:51:44 GMT

Hi Srilavi,

Inner join is a statement which is used between more than one Db table.

For all entries is a statement which is used between an internal table and a Db table.

We cannot always say that a join is better than For all entries or vice-versa.

It depends.

The join's performance will always remain the same.

However, for all entries poses an interesting scenario.

Performance would differ if you interchange the tables.

For eg.

Statement 1 : select * from B for all entries in A.

Statement 2 : select * from A for all entries in B.

The above statements would give different performance results.

It all depends on the entries in Production.

Generally it is seen that a join yields better performance.

Regards,

Ravi