Solution : https://service.sap.com/sap/support/notes/1654485 (SAP Service marketplace login required)
Key words : 
1 sp09 - change list #99632o, newer db2/zos client, db2/zos client, - change list #99619- mdm 7, - change list #99630- mdm 7, client versions prior, working thread failed, mds server log, contact customer support, archiving method=trueo
Related Notes : 
       
| 1660707 | Unarchive fails - "failing statement SET CURRENT SCHEMA" | 
| 1655215 | SAP Release Note for MDM 7.1 SP08 Patch07 | 
| 1655214 | SAP Release Note for MDM 7.1 SP07 Patch28 | 
| 1633585 | Archive operation fails with "General error" on DB2 on zOS |