Arnold Rots on the end of RFC

From: Jeff Lusted <jl99-at-star.le.ac.uk>
Date: Fri, 04 Jul 2008 12:27:45 +0100

Hi Pedro!

I was wondering how you intended to deal with Arnold Rots' points about the end of RFC. I thought Pat's replies vis-a-vis region were good enough. And in my opinion the date/time situation is OK for the moment: we never said this version was the last word in ADQL!

We've moved away from an XML based standard in order to make things easier for astronomers who want to construct queries in ADQL. I'd like to reiterate that Arnold's stand on using STC-s will make complex queries more difficult without inventing some other parsing mechanism.

For example, it would make the following query more complicated to format, and even more difficult to diagnose any formatting problems, and therefore subvert the reason for moving to ADQL as a plain text (BNF based) standard. It should be important to know whether a query is feasible ideally before it gets to the point of execution! The ADQL standard plus TAP should be more than adequate in that respect.

• Find all observed objects within 0.001 degrees of those
• observed objects which have a quality greater than 3
• and a redshift greater than 1.6 select s1.csys, s1.obsra, s1.obsdec, s1.z, s1.specid, s1.targetname, s1.quality from spectra as s1 JOIN spectra as s2 ON INTERSECTS( POINT(s1.csys, s1.obsra, s1.obsdec), CIRCLE(s2.csys,s2.obsra, s2.obsdec, 0.001) ) = 1 where s2.quality > 3 and s2.redshift > 1.6 ;

Hope this helps. Let me know if I can help directly... I didn't want to add anything new to the RFC page.

[ I have been thinking that the only way of "resolving" this argument to Arnold's satisfaction would be to mandate that the output to parsing ADQL should be STC compliant in some way, either STC-s or STC-x. Both of these are do-able. However, such a change will take us back to a working draft, and as far as I can see would be unlikely to get complete TEG support. ]

Regards
Jeff
--

Jeff Lusted               tel: +44 (0)116 252 3581
Astrogrid Project         mob: +44 (0)7973 492290

Dept Physics & Astronomy email: jl99-at-star.le.ac.uk University of Leicester web: http://www.astrogrid.org Received on 2008-07-04Z13:27:28