Solution : https://service.sap.com/sap/support/notes/531923 (SAP Service marketplace login required)
Key words : 
start date / end date            ->  logdatestart time / end time            ->  logtimechanged, db query>table key                        ->  logkeytext object, secondary index remains preserved, change                  ->  optypetransaction code                ->  tcodetable, delete long text logs, terms audit trail, extract table fields, prerequisites prerequisite rel, secondary index tabname, indexes depends extremely
Related Notes : 
       
| 1058984 | Frequent audit trail problems (transactions AUT01-AUT10) | 
| 667871 | AUT_DEL: Additional deleting-procedure | 
| 579980 | Table logs: Performance during access to DBTABLOG | 
| 539394 | AUT10: Performance improvements | 
| 529676 | AUT10: Background processing / variant call | 
| 522889 | AUT05, AUT_DEL: TIMEOUT | 
| 44341 | Customer-specific indexes |