Solution : https://service.sap.com/sap/support/notes/1461056 (SAP Service marketplace login required)
Key words : 
terms copy db2 r3ta r3load reason, r3ta based table splitting, db2 fast load, -table -tbname-+-partnum-, system copy guides, folowing circumstances apply, index -table-~img, additional secondary index, system copy, db2 supports
Related Notes : 
       
| 954268 | Optimization of export: Unsorted unloading |