I just tested selecting an XMLTYPE column over 32K in size and it worked ok. But for inserting, there seems to be a 4K limit, and even with sqlldr I'm having trouble loading really large documents. Since you need to bind an in/out parameter, maybe you hit that limit? Perhaps create a PL/SQL block that returns a cursor for selecting your data, and then select from that cursor?
in reply to Re^2: DBD Oracle ORA_XMLTYPE Seg Fault
in thread DBD Oracle ORA_XMLTYPE Seg Fault
Update: Selecting an XMLTYPE column over about 50K gives me an ORA-12152 (~50K) or ORA-0600 (> ~64K) error on $dbh->disconnect...but it does select the data. Weird...