Server-side Operations for Data Access version 1.0 Proposed Erratum 1: ID parameter UCD amendmentAuthor: Marco Molinaro Date last changed: 2019-04-18 | ||||||||
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< < | <-- Date accepted|rejected: 20NN-MM-DD --> | |||||||
> > | Date accepted: 2019-05-12 | |||||||
RationaleThe SODA (version 1.0) protocol uses the ID parameter to specify opaque identifiers to the dataset or file to be accessed. Three-factor semantics (Name, UCD, Unit) was mainly thought for interpretation of custom parameters in service descriptors. In the case of a parameter that is part of a standard, like the above SODA ID, the definition of the parameter is unambiguous. However a 3-factor description is still useful for homegeneity and comparison to other parameters. The UCD specified in the SODA-embedded 3-factor semantics is reported in the REC text asmeta.ref.url;meta.curation.SODAThis is not a valid UCD both for the, probably, typo of the added .SODA part and the fact that meta.curation identifies a man/organization responsible for the data as per the UCD vocabulary. To remedy the situation we propose here to use meta.id;meta.dataset instead. This achieves:
Erratum ContentThis Erratum proposes the following changes.ID descriptionIn §3.2.1 "*ID*" of SODA-1.0, update the UCD in the sentenceThe UCD describing the ID parameter is meta.ref.url;meta.curation.SODAfrom meta.ref.url;meta.curation.SODAto meta.id;meta.dataset Three-factor tablesIn §3.5 "*Three-Factor Semantics*" change the UCD value for the ID parameter in Tables 3 & 4 from frommeta.ref.url;meta.curationto meta.id;meta.dataset SODA sync service descriptor exampleIn the example in §4 "*Integration of Service Capabilities*" change the ID PARAM from<PARAM name="ID" ucd="meta.ref.url;meta.curation" ref="idcolumn-ref" datatype="char" arraysize="*" value="" > <DESCRIPTION>The publisher DID of the dataset of interest</DESCRIPTION> </PARAM>to <PARAM name="ID" ucd="meta.id;meta.dataset" ref="idcolumn-ref" datatype="char" arraysize="*" value="" > <DESCRIPTION>The publisher DID of the dataset of interest</DESCRIPTION> </PARAM> Impact AssessmentBeing the UCD is only used in SODA to uniquely describe the ID parameter using the 3-factor semantics, this change will have a minimal impact on the service provider's side (requiring the UCD amendment and releasing it). On the client side, changing a UCD will break clients using 3-factor semantics to find the parameter to pass the identifier in. However, as ID is defined by both Datalink and SODA and no competing definition ever existed, no known client actually uses 3-factor semantics to locate the ID parameter and instead just uses the hard-coded name ID. Hence, to our knowledge the UCD changed here is ignored by clients, and no breakage will occur. The safety of changing this UCD is also plausible in view of the fact that several data centers (e.g., GAVO's Heidelberg data center; example here) have been successfully operating SODA services that used meta.id;meta.main as a UCD for ID without interoperabilty issues.<--
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