Fabio,

>3.
>complex:
>a complex application has 10000 select and allows to combine her in 10000 ways,
>in this case a lot of UNION can unite select with different names;
>is it reasonable to impose that all the select have the same names to be able to unite her?
>This is not a restriction in SQL.

Well let's see. If you only aliased the first select and none of the other 9,999 SELECT statements you'd get the desired end result and have saved several hundred thousand keystrokes and gained a significant reduction in the size of the executable.

So that would be my suggestion. You are free to ignore it if you disagree with it.