ADQL simplified

[Wil O'Mullane]

> When you mention the query will " ... include a reference 
> to the datacenter/registry entry it is expected to run on ",
> I'm assuming that since the ADQL will reference a particular
> table (VOResource) then its description should be same regardless
> at which data centre it as at (the same table might be 
> replicated at various data centres).
To follow your SQL analogy you would assume that a table named 
X was the same in any SQL database. 
This is probably not a particularly fair assumption.

ADQL allows for an alias representing the archive to appear in
front of the table name. 

There is noting in the ADQL spec as of now to force to destination of the
query to be in the query. I do not think that is a necessary or
good idea.  It seems however some people feel ADQL will linger and
they will be unable to know what it was meant to do and what the
types of the columns were without know where it was intended to go to.
> 
> So the column based type information need not be included 
> in the ADQL itself, but it can be determined during query 
> processing (ADQL->SQL).
Correct - each NODE publishes its type info and the assumption is
the ADQL coming to it is in the correct types and UNITS!

But since SQL is as typeless as ADQL I fail to see what extra processing you have to do here.