Data Access Layer Working Group sessions Oct 16-17, 2003 at InterOpOct2003
Chair: Doug Tody [DT]
Minutes: Markus Dolensky [MD]
There were about 40 participants.
Content:
Overview of DAL types of data, DT
SIA V1.1; key issues, DT
- dataset IDs
- component data models
- access reference templating
Q: How to deal with uniquness of a dataset identifier?
A: Within authority ID domain data IDs assigned by each authority. One 'can' state that a ID is a replica, but this is not ensured.
Q: How to state data quality?
A1: Part of data model and characterization of data.
A2: Resource metadata allows have basic quality description of data collection.
Q: What about IDs of OTF processed products?
A: Goes to deeper question of what does it mean to publish data to the VO?
IDs do not change, but data may go away.
Proposed evolutions for SIA, Francois Bonnarel
- URL templates to get less verbose output
- factorization of repetitive cell values
- data model serialization
- Question: Would XSLT or Xpath be the right way to implement URL template resolution?
- Francois asks for feedback to be sent to dal@ivoa.net
SSA Overview, DT
SED Intro, MD
- This lead to a discussion about properties and query parameters that SSA services should recognize and support. See presentation (.pdf, .ppt)
- Some missing bits were identified:
- definition how to group parameter blocks; i.e. chunks of points with common meta info
- reference frame (e.g. velocity frame, rest frame)
- follow above link for intro to modeling effort
- Suggestion: Use term "samples"
- Note that model also is supposed to cover SEDs
SSA Issues (discussion)
- add query parameter for spectral resolution
- Suggestion: Find more use cases
- About formats: VOtable, text, fits binary table or image, graphics
Q: Conversion support for units needed?
A: No.