Solution : https://service.sap.com/sap/support/notes/1656672 (SAP Service marketplace login required)
Key words : 
sql server tp getdbobjsize returns wrong values, made schema/user mismatch resistent withsap kernel 7, terms ehpi getdbobjsize trigger reason, tp getdbobjsize returns size 0, schema/user mismatch, serioud performance issues, cloning process starts, copy huge amounts, ehpi updates, computed size
Related Notes : 
       
| 1690835 | MSS: Add. Info. - Software Update Manager 1.0 SP4 | 
| 1678749 | R3szchk computes size 0 for all tables and indexes | 
| 1612995 | MSS: Add. Info. - Software Update Manager 1.0 SP3 | 
| 1161733 | SQL Server: SAP EHPI for SAP NetWeaver 7.0 | 
| 1086375 | User ID/Schema ID inconsistency in SQL database |