ADQL-2.1 internal draft

[Walter Landry]

Marco Molinaro <molinaro at oats.inaf.it> wrote:
> Dear DAL members,
> a first internal draft of the ADQL-2.1 document in available online,
> linked on the IVOA TWiki at
> 
> http://wiki.ivoa.net/twiki/bin/view/IVOA/ADQL

Here are some of my thoughts.  

1) Coordinate systems are deprecated in the geometric functions (BOX,
   CIRCLE, etc.).  Why don't we just declare new functions that do not
   take the first argument?  So instead of

     BOX('', 25.4, -20.0, 10, 10)

   it would be

     BOX(25.4, -20.0, 10, 10)

   The functions have different arity, so it is easy to distinguish
   between them in the parser.  In general, empty strings feel odd to me.

2) I do not understand the syntax for IN_UNIT().  Shouldn't there be
   three arguments (value, units_from, units_to) and not two?

3) Section 4.6.1 has a cliffhanger ;)

4) Can we put the math and trig functions into the optional
   components?  Most of them are not implemented in sqlite.

5) Why are we making new function names BIT_AND, BIT_OR, etc?  Why not
   just use the operators?  It is what everyone but Oracle and
   Informix implement, and they use different names anyway.

Thanks,
Walter Landry