1. May 2006IVOA Victoria, Canada1 VOQL Where do we stand? What is left? Yuji Shirasaki JVO Maria A. Nieto-Santisteban JHU T HE US N ATIONAL V IRTUAL O BSERVATORY

2. May 2006IVOA Victoria, Canada2 Agreed (IVOA – Madrid Spain) First, Get WD -> PR -> Rec Finish WDs: –Nov 15 –Open for comments within WG: 2 weeks (end of Nov) –Promote to PR (needs at least a month) –Promote to Rec (needs approval from Exec) Implement changes & Upgrade by –March 1 st 

3. May 2006IVOA Victoria, Canada3 VOQL Roadmap 05-06 (Oct – 7 th 05) JVO will release a new SkyNode toolkit in October (done in May 06) ------------on the tap for future ------- The '!' operator problem. Need for proper footprints More flexibility for XMATCH –How do we include errors? –new algorithms SkyNode -> High level data access service? ADQL/x ADQL/s what do we really need? Include VOStore – Async mech. Inclusion of simulated data access (with theory IG) Jan 2006NVO demos Spring 2006 reference implementation ? May 2006InterOp WS in Canada Aug 2006 IAU Prague : VO Special Session Autumn 2006InterOp WS in Russia

4. May 2006IVOA Victoria, Canada4 ADQL Where do we stand? What is left? Maria A. Nieto-Santisteban Johns Hopkins University T HE US N ATIONAL V IRTUAL O BSERVATORY

5. May 2006IVOA Victoria, Canada5 ADQL Specification status ADQL WD V1.04 –One specification but two flavors of BNF (Appendix/ CORE-Appendix) do we have a preference? –The Restriction / Extension section structure doesn’t work any longer. The document needs to be restructured Is the CORE Specification (.xsd) ready to be approved and implemented? Is the FULL Specification (.xsd) ready to be approved and implemented? Are we closer or further to reach the PR point? Focus on What is –Mandatory / Desirable / Optional ? GOAL?

6. May 2006IVOA Victoria, Canada6 What should be our GOAL? SIMPLICITY Differ from SQL as minimum as possible! Define the minimum required to start implementing services compliant with ADQL 1.0

7. May 2006IVOA Victoria, Canada7 Under debate Alias –Mandatory or Optional? Comments –Do we need comments? CaseSensitive –Why/How/When did this get into the CORE ADQL? Select …. into ‘VOS:….’ –Is Create / Insert a feasible option?

8. May 2006IVOA Victoria, Canada8 Under debate Default units in the REGION constraint –ArcMinutes / Degrees / Arbitrary? Default frame in REGION Select * From table Where Region('CIRCLE 0 0 10') –Do we have users (or developers) that lazy? Time type: strongly suggestion (from Arnold) for the ISO case to adopt the same restrictions that are in FITS and in STC: yyyy-mm-ddThh:mm:ss.s..., optionally dropping the 'T' in SQL conversion; no support for time zones o

9. May 2006IVOA Victoria, Canada9 Under debate XMATCH –Where should XMATCH go? FROM | WHERE? SELECT s.ra, s.dec, t.ra, t.dec, x.d, x.ra, x.dec FROM SDSS:PhotoPrimary s, TWOMASS:PhotoPrimary t WHERE XMATCH(s,t, 3) OR SELECT s.ra, s.dec, t.ra, t.dec, x.d, x.ra, x.dec FROM SDSS:PhotoPrimary s, TWOMASS:PhotoPrimary t, XMATCH(s,t, 3) x

10. May 2006IVOA Victoria, Canada10 Under debate Are XMATCH_CHi2 and XMATCH_Distance syntactically different? –XMATCH_CHI2 (s, t, sigma) –XMATCH_Distance (s, t, distance) –What does it mean? Xmatch is expressed by a FunctionType wrapped by booleanValueFunctionType

11. May 2006IVOA Victoria, Canada11 SkyNode Where do we stand? What is left? Maria A. Nieto-Santisteban Johns Hopkins University T HE US N ATIONAL V IRTUAL O BSERVATORY

12. May 2006IVOA Victoria, Canada12 SkyNode Specification status SkyNode WD V1.02 Are we closer or further to reach the PR point? Focus on what is –Mandatory / Desirable / Optional ? GOAL?

13. May 2006IVOA Victoria, Canada13 What should be our GOAL? SIMPLICITY Define the minimum required to start implementing services compliant with SkyNode 1.0 to allow data access and basic spatial XMatch

14. May 2006IVOA Victoria, Canada14 Under Debate Request to remove references to portals and the SkyQuery origin in the introduction What is an error versus a service failure? What are special exceptions? Feature table needs to be finished ADQL-Features table needs to be finished Update to the new VOResource metadata schema How do we enforce good metadata? Metadata through ADQL, why not/why yes? Shall we split the spec between BASIC SkyNode and Full SkyNode?

15. May 2006IVOA Victoria, Canada15 Under Big Debate XMATCH semantics –XMATCH_CHI2 –XMATCH_Distance Both must be CLEARLY defined in terms of inputs and outputs How does it work for 2 nodes, 3 nodes, n nodes …? Does it bring always the same results?

16. May 2006IVOA Victoria, Canada16 Under Big Debate: the XMATCH XMATCH_Distance (s, t, D) Output_table (,, d) d D

17. May 2006IVOA Victoria, Canada17 XMATCH_Distance (s, t, k, D) First Step Output_table (,, d) Second Step Output_table () -- empty Under Big Debate: the XMATCH d D d’d’

18. May 2006IVOA Victoria, Canada18 XMATCH_Distance (t, s, k, D) First Step Output_table (,, d ) Second Step ? Output_table (,, d ) (,, d’ ) Under Big Debate: the XMATCH d D d’d’

19. May 2006IVOA Victoria, Canada19 Under Big Debate: the XMATCH XMATCH_chi2 (s, t, l) Output_table (,, d,, likelihood) r r < search radius given threshold l and SkyNode positional error

20. May 2006IVOA Victoria, Canada20 XMATCH_chi2 (s, t, k, l) First Step Output_table (,,, likelihood) Second Step Output_table (,,,, likelihood’) Under Big Debate: the XMATCH rd’d’ r < search radius given threshold l and SkyNode positional error