1876633 - Crystal reports based on multiple Function Modules takes long time to refresh.

Performance issue with Crystal Report based on multiple Function Modules.

• SAP Crystal Reports 2011
• SAP R/3

1. Create a blank report using SAP Tables, Clusters and Functions driver using Crystal Reports.
2. Select the SAP R/3 system from the Available Systems list.
3. Select the Function Modules. For e.g. add Function Modules with name FM1, FM2 and FM3 to the Selected Tables list. 
4. Join the Function Modules in Link tab in Crystal Reports designer.
5. The report takes longer time to refresh than the report created using only one Function Module.

When using Database Expert for the join, the join occurs after the data is fetched from the Function Module. The child Function Modules will pull in all records regardless of parent Function Module. or will be executed repeatedly for each record retrieved in parent FM.

On the other hand, incase of sub-reports, then Crystal Reports will make multiple calls to the "child" Function Module for each record retrieved in parent Function Module.

Modify the Function Module so that all data comes from one Function Module and, thereby, remove the join in Crystal Reports.

Performance issue in CR Function Modules, SAP R/3 slow crystal reports , KBA , BI-RA-CR , Crystal Reports designer or Business View Manager , Problem