Solution : https://service.sap.com/sap/support/notes/487676 (SAP Service marketplace login required)
Key words :
alter table add primary key reason, 'alter table add primary key' command, > -> edit -> extras -> force conversion, call transaction /nse 14, database versions version <= 7, table definition, affected table, data record, fields greater, long columns
Related Notes :
| 481982 | "Connection closed" error with the SAP DB database |
| 397652 | SAP DB Release upgrade to 7.3.0 B14/15 |