ADQL v0.7.3

[Wil O'Mullane]

Perhaps Masatoshi can comment but I would like an XSD to be going on
with for development. 
The Paper specification we can work some more on but I would also like that we could move that to Recommendations for or before the IVOA meeting in May.
I think tat will be facilitated by having some working stuff with the XML.
wil
On Wed, Mar 03, 2004 at 03:49:25PM -0600, Ray Plante wrote:
> A couple of quick comments on v0.7.3.
> 
> First, on inspection of the examples, this looks a lot nicer.  I've asked 
> Ramon to create a new stylesheet for this version; that may ferret out 
> other issues.
> 
> On Mon, 1 Mar 2004, Tony Linde wrote:
> > We need a clear statement of how the current v0.7.3 is generated (and also
> > how v0.7.1 aka 0.8 was generated). 
> 
> Just for clarification, what is the motivation here?  If it is just so 
> that we understand the development process, this would certainly be good 
> to have.  If the statement is intended for the specification, this may or 
> may not be needed.  
> 
> For the spec, what we need are definitive statements about what defines 
> the ADQL syntax and semantics.  We have two choices:
> 
>   o  We say that ADQL/x is defined by a schema derived from this process.... 
>      This would presumably incorporate the derivation of the ADQL/s
>        or
>   o  We say that ADQL/x is defined by this XML Schema (in the appendix)....  
>      In this case, we also need to spell out, 
>        1.  Precise definitions of each element in the schema.
>        2.  How it maps to ADQL/s
> 
> My complaint with the last draft of the spec was that it really didn't do 
> either.  
> 
> With regards to the cardinality issue, I am against the idea of allowing 
> 2* for functions like add, div, and, & or.  These are mathematically 
> defined as two-operand operations, and so our XML model should reflect 
> this.  The fact that it raises the issue of order of operation is a good 
> thing; we must deal with this.  
> 
> As I've mentioned, my own reading of the SQL-92 standard suggests that 
> ANDs and ORs are evaluated left-to-right in the absence of parentheses; 
> however, I don't feel 100% on this.  The alternate interpretation would be 
> that its system dependent.  Since we are developing ADQL for 
> cross-database queries, I don't think this latter state is good one to be 
> in.  
> 
> cheers,
> Ray