--- In firebird-support@yahoogroups.com, "Thomas Steinmaurer"

> SELECT COUNT(*) FROM (
> SELECT .... HUGE_FIELD_LIST ... FROM .....
> )

[skip]

> Right, perhaps the example is somewhat CONSTRUCTED *g*, but
> in some situations derived tables are useful. ;-)

And this is the only case which can't be achieved using joins,
sub-selects and exists IMHO. Two or three times in my life I wanted
this :)

Best regards,
Alexander.