Solution : https://service.sap.com/sap/support/notes/700675 (SAP Service marketplace login required)
Key words : 
informix dynamic server versions---------------------------------               table 0, individual upgrade-phases----------------------------------------               sql error 242, 1 platform database release aix   9, 2 platform database release aix   9, informix dynamic server version, informix dynamic server, individual upgrade-phases 6, operating system platform, informix-specific problems, open database table
Related Notes : 
       
| 788218 | Add. info. on upgrading to SAP ERP Central Component 5.0 SR1 | 
| 689574 | Add. info. on upgrading to SAP ERP Central Component 5.00 |