Hi Osvaldo, Alway post the full error: E_OP0487_NOEQCLS consistency check - no joining equivalence class found when expected Also seen with: E_OP0901_UNKNOWN_EXCEPTION Unknown exception occurred in optimizer utility. Value is 68197. I had a similar error on 2.6, AIX 5.2 a while ago, caused by a BIG bit of SQL, it brought down the iidbms in fact. The system had run out of OPF Memory. If your symptoms are similar to the above, I suggest you re-configure the system (use cbf) with a big amount of OPF Memory and re-start Ingres. Good Luck Steve