Today i was refreshing a MVIEW (Oracle 9.2.0.1.0 on Windows 2000) and instead of writing

exec dbms_mview.refresh('SCHEMA1.MVIEW1','C'); 

i wrote

exec dbms_mview.refresh('SCHEMA1','MVIEW1','C');

And it gave me:

ERROR at line 1:
ORA-30019: Illegal rollback Segment operation in Automatic Undo mode
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 794
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 851
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 832
ORA-06512: at line 1

which has nothing to do with the real error. Take care !