nvl() and coalesce() with Oracle 8
When coalesce() is called with only 2 arguments and Oracle 8, it should use nvl(). (Oracle 9i supports coalesce)
It would also be nice to support the "nvl()" function across the board and simply translate it to coalesce() if called from any database besides Oracle.
In sqlserver it is ISNULL() Some databases may use VALUE()
Mysql might support coalesce, otherwise IFNULL()
I believe ansi is coalesce()
See also #1758