Solution : https://service.sap.com/sap/support/notes/859456 (SAP Service marketplace login required)
Key words : 
avoid additional wait time, additional queue time, composite sap note 567746, performance extraction reason, terms query, query depends, parameter settings, customer exits, olap cache, save results
Related Notes : 
       
| 1275248 | Selective logging on OLAP cache activities | 
| 1107434 | OLAP cache consultation: Long wait times due to locks | 
| 1105139 | Filling the OLAP cache with "contains pattern" in BI 7.0 | 
| 959405 | Cache enqueues are not set | 
| 921951 | Format error with IMPORT: No other container found | 
| 856226 | Logging mechanism to analyse Cache related problems | 
| 836439 | SAPBWNews BW Support Package 14 NW'04 Stack 14 RIN | 
| 807967 | Filling the cache from the Reporting Agent | 
| 783252 | SAPBWNews BW 3.1 Content Support Package 22 | 
| 783170 | SAPBWNews BW 3.0B Support Package 28 | 
| 456068 | OLAP: Deactivating query cache/deleting cache data |