What is the difference between Function groups and Function pools?

[Former Member]

Hi all,

Please point to some tcode or program in the SAP system...

Thanks,

Charles.

[ferry_lianto]

Hi,

Function pool is nothing but an abap program where you can define function modules. When you call a function module from a function group that has not already been loaded in an internal session, an additional program group is created and into which the function group to which the function module belongs is loaded. The additional program group, along with its data, exists for the rest of the time of the internal session. For this reason function group must begin with a function pool statement.

You can use transaction SE80 and SE37 to see both example of function group and function pool.

Regards,

Ferry Lianto

[RichHeilman]

Really, these terms are essentially the same thing. Sort of like how Type groups and type pools are the same thing.

Regards,

Rich Heilman

[RaymondGiuseppi]

Look at thread

<b>FUNCTION-POOL</b>

The introductory statement FUNCTION-POOL declares a program in which you can define function modules. At runtime, function pool programs are loaded in to a new program group with their own user dialogs and their own shared data areas in the internal session of the calling program. For this reason, function groups (type F programs) must always begin with a FUNCTION-POOL statement. This is usually generated by the Function Builder. Type 1, M, or S programs should not begin with a FUNCTION-POOL statement, since they would then not share common data areas with the caller. <b>However, in exceptional cases, you can introduce a type 1 or type M program with FUNCTION-POOL to ensure that externally-called subroutines can process their own screens</b>. As in the REPORT and PROGRAM statements, you can specify the message class and standard list formatting options of the program in the FUNCTION-POOL statement.

<b>Function Groups</b>

Function groups are containers for function modules. You cannot execute a function group. When you call an function module, the system loads the whole of its function group into the internal session of the calling program (if it has not already been loaded). For further information, refer to Organization of External Procedure Calls.

So Most Function pools are Function Groups, and in rare case we can have type M program too.

Regards