Solution : https://service.sap.com/sap/support/notes/822302 (SAP Service marketplace login required)
Key words : 
/saphelp_nw04/helpdata/      de/57/b10022e849774f9961aa179e8763b6/content, virtual characteristics/key figures, virtual characteristics/key figs, parent/child node assignment, -transactional operational data store, transactional operational data store, time-specific navigation attributes, adding exchange rates, user exit rsr00002, query key date
Related Notes : 
       
| 1681396 | Query Performance | 
| 1138864 | Delta procedure of the OLAP cache | 
| 891029 | RSR00002: Virtual chars and key figures in reporting | 
| 829348 | Part provider invalidates OLAP cache although it is not read | 
| 798800 | |
| 750074 | New exchange rates are ignored | 
| 733296 | Characteristic as InfoProvider: Time stamp for OLAP cache | 
| 730236 |