Solution : https://service.sap.com/sap/support/notes/132290 (SAP Service marketplace login required)
Key words : 
sqlstate=57011 additional key words lockescalation, 'st04 -> detail analysis menue -> performance', application error / suboptimal customizing 2, db2 update db cfg, single table accesses, unnecessary table scans, db error occurs, avoid error sql0912, database parameter locklist, bad performance
Related Notes : 
       
| 175036 | DB6: The DBSL deadlock trace | 
| 83819 | DB6: Collecting support data | 
| 40024 | Transferring customer files to sapserv# using ftp | 
| 38513 | Database trace (db2trc) with DB malfunctions | 
| 31707 | DB6: DBSL trace for performance/error analysis |