Solution : https://service.sap.com/sap/support/notes/417598 (SAP Service marketplace login required)
Key words : 
posted additional key words rescheduling, initial data retrieval, prerequisites solution correction, symptom low performance, sales orders, performance
Related Notes : 
       
| 610704 | Composite SAP note: Performance of SD document update | 
| 609435 | Composite SAP note: Performance in backorder processing | 
| 460160 | Comp. SAP note: Queue error with liveCache RC 41 and 147 | 
| 420681 | ATPFIELD is filled with unnecessary information | 
| 394088 | APO customer requirements performance | 
| 375193 | Backorder processing: Composite SAP note on posting | 
| 370601 | Composite SAP note: APO 3.0 and 3.1 performance | 
| 350804 | Message handler: Performance improvement | 
| 335466 | APO: Change Priority, Underdelivery Tolerance, Overdelivery |