In re-working some old reports that I'm still maintaining, I decided to clean up instances of "WHERE foo > bar or foo is null" with some LNNVL() loving. Given the nature of my query and of LNNVL(), I plugged in LNNVL(foo > bar) and prefaced it with a NOT, since LNNVL() will return false when I want thing to evaluate to true. This was met with furious anger:
ORA-03113: end-of-file on communication channel
It kills my database connection! I headed over to Metalink and found Bug 4211527, reported over 2 years ago on 10gR1, with no workaround. I confirmed the bug is still around in Back to the OR statement for me.