'AS' - ADQL WD v1.05

I notice that alhough table aliases are required, it is optional whether the 'AS' keyword is used to denote this. I'd argue that having optional syntax doesn't help implementors, and is just confusing to users. Furthermore, I don't think the statement on page 4 "ADQL/s and ADQL/x are translatable to each other without loss of information"

is possible, considering optional syntax, unless the adql/x version has a way of recording which optional fragments of syntax have been used (and I really hope this isn't the case).

so I'd say choose one, either one, but don't include both.

same applies to column aliases too.

---
http://wiki.astrogrid.org/bin/view/Main/NoelWinstanley
Senior Java Developer, AstroGrid Project
Jodrell Bank Observatory, University of Manchester