Registry Sessions at the May 2008 Interoperability Meeting

Moderator: Aurelien Stebe

Registry Sessions at the May 2008 Interoperability Meeting

Plenary 1 (Monday, 11.00)

Topic	Presenter	Materials
Status & Goals	Aurelien Stebe	ppt

Reg 1: Integration and Interoperability (Monday, 14.30)

In this session we will discuss any remaining issues related to our transition to the v1.0 Registry Interfaces standard. If you would like to formally present a report or raise issues, please add your name to the agenda below.

Topic	Presenter	Materials
Astrogrid status	Kevin Benson	pdf
...

Notes

Reports by the various Registry Providers :

Kevin Benson (Astrogrid) : over a year working, [[http://www.astrogrid.org/wiki/Home/AboutAGDesktop][VODesktop] using it, support for VOSI, XQuery interface (see presentation for more details).
Gretchen Greene (NVO/STScI) : RofR is a big success, watch closely how clients will handle the new multiple capabilities services resources.
Matthew Graham (NVO/Caltech) : issue with UTF-8 not correctly encoded on some resources; ask Ray if this can be added to the Validator.
Sebastien Derriere (CDS) : Validator is very useful, less resources than before (nearly half, using service-centric, rather than table-centric).

All Registry Providers reported minor glitches with specific resources; (nearly)-all were fixed; was to be expected, nothing too serious.

Talks on the "xsi:type" issue and general namespace short-names :

Proposition from Kevin Benson to mandate the namespace short-names (scs:, sia:, ssa:) for easier querying and XPath resolving.
Proposition from Aurelien Stebe to use VOStandard to register those in the RofR just like the "standardID".
General agreement that it would ease things for many people, and to investigate/test this until next InterOp and report there.

Proposition to have the Validator run periodically instead of single run on registration. Comment by Thomas McGlynn that this is in the work at NVO using Ray's Validator. Comments to have it fill a report page on the RofR webpage or even fill the "validationLevel" element.

Report by Evanthia Hatziminaoglou of the ESO SSAP resource not being transfered correctly to other Registries because of space characters in the identifier. Problem will be resolved after the session.

Thomas McGlynn asking if there is a date planned to encourage client applications implementations to transfer to the new Registries. Consult with Ray Plante.

Confirmation of agreements talked about on the mailing list concerning "deleted" records :

"deleted" records are allowed to be actually dropped completely after 6 months
GetResource and XQuerySearch are the only two Search methods returning "deleted" resources
calls to OAI harvesting methods should return "current" resources (not "deleted") if no date filter is used

Kevin Benson to add those to the RI document before it goes to RFC.

Talks about the "multiple schema versions" issue :

Clients must check the namespaces for versions they support.
Proposition from Aurelien Stebe to send a mail from the Registry WG to the Applications WG informing application implementors of the issue.
Proposition from Gretchen Greene to have the Registry list all the namespaces it might return on a search query inside its resource record.
Proposition from Aurelien Stebe to use a test Registry (isolated from the rest) with multiple schema versions for client application tests.
List of known client applications using the Registry : VODesktop, Aladin, VOSpec, a VOTech tool (to check).

Reg 2: Registry Extensions (Tuesday, 11.00)

In this session we will primarily discuss the standardization of various registry extension schemas, primarily VODataService and VOStandard. Revisions to VODataService will require an uprev of the schema to version 1.1, so we will also discuss if there are any issues supporting v1.0 and v1.1 simultaneously.

Topic	Presenter	Materials
Intro, versioning schemas	Aurelien Stebe	ppt
VODataService	Guy Rixon	see end of TWiki page for proposed schema
...

Notes

A question on keeping or not "SkyNode" in the schema roadmap started a review of the schema responsibilities :

SimpleConeSearch and SimpleImageAccess will be completed and pushed to REC status by the Registry WG.
SkyNode is also under the Registry WG, but the effort to make it a REC will be reviewed when we get to it.
SimpleSpectralAccess will be completed and pushed to REC status conjointly by the Registry and DAL WG.
All other schema extensions are the responsibility of each Spec authors and should be attached to the Spec.

Presentation (see above PowerPoint file) on the schema roadmap, VOResource TWiki page with extension How-To, "what makes an extension schema IVOA official" and the risks involved in multiple schema versions (see Session 1 Notes above for more infos on this).

Discussions on proposed modifications to the VODataService schema :

All proposed modifications on the last slide of above PowerPoint presentation are accepted, except following point.
Doug Tody's proposition to change "table" 's "role" attribute is postponed, depends on the result of the TAP discussions. (questions on the utility of the table/view separation)
Matthew Graham proposed to add an optional "responseURL" to the "sampleQuery" pointing to the expected result -- accepted.
Guy Rixon presented more substantial modifications for the TAP/QL protocol (see schema posted on above VODataService TWiki page). (confusion on astro- / database- usage of "Catalogue")

TAP required modifications will be reviewed further and follow the protocol evolutions and discussions over the summer.

First half of discussion on Gretchen Greene's proposition to add an optional ADQL/VOTable search query method to the Registry interface. The idea is to have something similar to TAP query using the SELECT part of ADQL with XPaths/UTypes in String form, getting the result in flat VOTable for easier client access to simple Resources common values. The RM values returned would be queried for, not determined by the Registry. Agreement it is an interesting idea, with quite a few technical difficulties. Further talks in Session 3.

Joint Session: VOSI (Thursday, 16.30)

See the Grid and WebServices page

Reg 3: Future Directions (Friday, 9.00)

Topic	Presenter	Materials
Controlled Vocabularies with Registries	Norman Gray	pdf
Astronomical Visualization Metadata (AVM)	Aurelien Stebe	ppt
Future of ADQL for Registries	Aurelien Stebe	ppt
...

Notes

Presentation by Norman Gray on Controlled Vocabularies with Registries (see above presentation).

Suggestion to add a multiple optional "subjectURI" element to VOResource to contain the vocabulary pointers (backward compatible).
Proposition from Guy Rixon to use the already present "subject" element and have the special behavior when the value is an actual URI.
Norman Gray agrees as long as it is technically viable, all agree second option is preferred if it is the only change request, first otherwise.

Short presentation (see above PowerPoint file) on Astronomical Visualization Metadata (AVM). Questions from Laurent Michel on the implementation and other details, Aurelien Stebe couldn't answer with precision and advised to contact Ray Plante directly.

Future roadmap, target dates and documents were discussed. See below PowerPoint file of the closing plenary session for the details.

Presentation (see above PowerPoint file) and short discussion on Future of ADQL for Registries. Aurelien Stebe presented the opinion and propositions of the ESA. Quite a few technical difficulties to deal with, but the approach should allow for a lot of code sharing with a TAP implementation. The issue is broader than the Registry WG and touches ADQL, VOTable, UTypes, UFIs ... Francois Ochsenbein noted that UTypes/UFIs should allow for fixed mapping and not dynamic parsing ; all agreed, but might not be possible due to DataModel. No decision taken, general feeling is we need working prototypes to prove solutions feasible.