Uploaded image for project: 'OASIS OSLC Lifecycle Integration Core (OSLC Core) TC'
  1. OASIS OSLC Lifecycle Integration Core (OSLC Core) TC
  2. OSLCCORE-111

Query spec and relative operators for string literals

    XMLWordPrintable

    Details

    • Type: Task
    • Status: Open
    • Priority: Major
    • Resolution: Unresolved
    • Component/s: Query
    • Labels:
      None
    • Proposal:
      Hide

      The spec should specify that support for ">", ">=", "<", and "<=" on string properties:

      1) is a MAY (and not the currently implied MUST).

      2) Where supported, the semantics are server dependent. Applications using RDBs might perform string ordering using locale-dependent collators. The spec should be persistence-agnostic. Requiring strict conformance with SPARQL is likely to be unimplementable on RDB based implementations.

      3) where not supported, specify that a server SHOULD return a 501 "Not Implemented" response with a response body being an oslc:Error that describes what is not supported, and if known and relevant, why.

      4) The spec should drop a requirement that relational operators MUST have SPARQL semantics. We should replace that with more specific requirements that are more easily adoptable.

      Show
      The spec should specify that support for ">", ">=", "<", and "<=" on string properties: 1) is a MAY (and not the currently implied MUST). 2) Where supported, the semantics are server dependent. Applications using RDBs might perform string ordering using locale-dependent collators. The spec should be persistence-agnostic. Requiring strict conformance with SPARQL is likely to be unimplementable on RDB based implementations. 3) where not supported, specify that a server SHOULD return a 501 "Not Implemented" response with a response body being an oslc:Error that describes what is not supported, and if known and relevant, why. 4) The spec should drop a requirement that relational operators MUST have SPARQL semantics. We should replace that with more specific requirements that are more easily adoptable.

      Description

      https://open-services.net/bin/view/Main/OSLCCoreSpecQuery says for comparison_op:

      "Semantics of datatypes and operations on these datatypes MUST work as defined in the SPARQL Query Language (reference: SPARQL). "

      This potentially makes the spec unimplementable on RDB based applications that probably form the vast majority of implementations. The specification should be persistence technology agnostic.

      The problem is that for string properties (and for URIs - see https://issues.oasis-open.org/browse/OSLCCORE-153), querying for ">", ">=", "<", and "<=" may be unimplementable, or the ordering might be determined by an RDB vendor and different from the SPARQL spec. For example, string order might be based on locale-dependent Collators that are often case insensitive.

        Attachments

          Activity

            People

            • Assignee:
              jamsden James Amsden
              Reporter:
              DavidHoney David Honey
            • Watchers:
              1 Start watching this issue

              Dates

              • Created:
                Updated: