Solution : https://service.sap.com/sap/support/notes/187147 (SAP Service marketplace login required)
Key words : 
util_execute set log mode demoyou, > set log mode demoyou, xsql show stat log, temporary log mode, log backups history, selecting info-> log, utility command line, sap db version 6, sap db version 7, form dual/demo
Related Notes : 
       
| 337733 | |
| 121245 | System settings for local currency changeover to euro |