Registry Sessions at the May 2010 Interoperability Meeting

Moderator: Ray Plante

Plenary 1 (Monday, 2:00pm)

Session 1: VOResource Extensions: VOStandard, RegSimpleDAL (Tuesday, 2pm)

Agenda:

Discussion Topic: Future Standards Efforts

With modest but persistent effort, we can easily complete the two pending standards in the next six months. Where should we go from here? Here are some thoughts from past IVOA discussions:

• VOApplications, an extension for registering tools, applications and software libraries, has been on our roadmap; however, last fall we concluded that motivation for registering applications was not very strong. Thus, this standard has been tabled for now. Has our outlook changed since then?
• The constraint-based search interface is less than desirable. Can we do something better?
• Standard for search results in VOTable format
• We would like to recognize and endorse Astronomical Visualization Metadata (AVM) as a standard.

We also have real need to put effort into operational kinds of activities (the theme for Thursday). Given limited person-power, how important are the potential new standards, compared to curation, validation of our current assets?

Notes:

New Naming convention:

We had been advised by the TCG to consider renaming VOStandard as this name could be confused with the IVOA Document Standards among those outside of the the Registry Working Group. RegSimpleDAL was observed to be more mysterious. We came up with a new convention for short names for RWG standards that are focussed on defining a registry extension and which would be applied to these two standards: subject + RegExt.

Thus, VOStandard will now be referred to as StandardsRegExt, and RegSimpleDAL will be referred to as SimpleDALRegExt. Ray will update the relevent documents and twiki pages.

RegSimpleDAL/SimpleDALRegExt

• If necessary, SSA will be split out of this document if necessary changes for this extension cannot be incorporated into this document when it is otherwise ready for PR.

• We should be sure this document includes a statement that accessURL values should end in either a ? or a &

The Search interface

• See Mark's slides for the Topcat experience
  • Mark uses the ivoaregistry Java library which returns results in DOM; the memory requirements can be quite large
  • One UKIDSS record is 11 MB
  • He replaced the DOM part with SAX streaming to extract the few things he was interested in
  • He offered to make this code available
• Interest was expressed in his SAX streaming; Ray would like to get it into ivoaregistry.
• A common use case for applications is to extract a small part of the description in a light-weight way. Any new search interface we consider should allow the client ask for the desired items.

Registry Interoperability

• Mark: serious problem with Euro-VO registry: use of LIKE in ADQL searches are case-sensitive.
  • errata to RI on this point?
• dynamic discovery of Registries via the standard search interface is apparently broken with all registries.

Future Directions

Ray: Current assessment of full constraint-based search interface:

• - Current based on deprecated version of ADQL
• - Certain kinds of query not possible
• + searching on any item is possible without change to standard

New search interface should include:

• searching on any item (or future item) without change to standard
• from Mark: ability to select what information to return

Possible directions:

• push XQuery for relational databases
• VOExplorer's Google-like syntax (title:LMC ability:TAP)
  • comment: it is sufficient to expose this at the tool level; rather than server interface level.
• ...

Kevin Benson shared some slides borrowed from a talk he saw about the Heliophysics VxO. This community is considering a Lucene-based syntax.

Session 2: Registry Curation and Usage (Thursday, 4pm)

Agenda:

Notes:

Plenary 2 (Friday, 9am)