Ah, yes, I forgot the case of the empty set. It's always the "Randbedingungen" that get you. Quoting Lex de Haan <lex.de.haan@xxxxxxxxxxxxxx>: > Wolfgang, > > this is all about null-values *and* empty sets. see below: > -- regards Wolfgang Breitling Oracle 7,8,8i,9i OCP DBA Centrex Consulting Corporation www.centrexcc.com -- To unsubscribe - mailto:oracle-l-request@xxxxxxxxxxxxx&subject=unsubscribe To search the archives - //www.freelists.org/archives/oracle-l/