Results from the Berlin Protocol Meeting

Minutes

The BerlinMeetingMinutes are available in a brief table form.

Changes agreed in Berlin

Improvement to the SecondProposal:

• Terminology
  • provider=host: a whole provider software installation
  • datasource=database="collection of objects": a single connected database or a datasubset e.g. visible through a view supporting different ConceptualSchemas
  • resource: a single datasource bound to a single ConceptualSchema
• AccessPoints
  • providers supporting all RequestTypes * metadata response returns metadata for the provider and all its datasources * capabilities response returns the capabilities for all datasources * initially do not merge responses from several datasources, although it might be desireable in the future, esp. for inventories.
  • datasources supporting all RequestTypes * metadata response returns metadata for the provider and this datasource incl all "resources"=schemas with their record numbers * capabilities response returns capability of this datasource. that is config&request type capabilities for each resource seperately
• Header
  • leave request attribute and generically name the element following header for all requests details "message"
  • source repeatable with sequence important and the first source element being the original source * source element keeps resource attribute to allow to specify origin of the data. might be repeated for a response of several datasources
  • destination element repeatable to submit distributed queries to several and single providers * destination element keeps resource attribute to allow adressing of several datasources within a single request to a provider
  • remove compression element
  • move detailed software/components complex type to provider related capability and just keep the overall versioning with BerlinMeetingResults>
• RequestTypes needed to be implemented:
  • PingRequest
  • CapabilitiesRequest
  • MetadataRequest
  • InventoryRequest
  • SearchRequest (see below)
  • open issue: CustomSearch needed?
• capabilities response, see CapabilitiesProposalThree
• metadata response, see MetadataProposalTwo
  • drop IPR, insert supported schemas incl record count
  • add logo URL
  • attach date-last-updated to resource
• SearchRequest (see SearchProposalTwo)
  • search based on the full/partial search for a single configured ConceptualSchema
  • allows to combine several schemas for a response (to use extension schemas) by specifying a list of qualified concepts instead. See SearchProposalTwo for details.
  • always returns a valid document. in case mandatory data is missing, drop the record or branch. dont use NULLs in response.
  • when requesting no concept at all, return only the mandatory concepts.
  • request the root node of a schema to retrieve the full document
  • allow to ask for BranchNodes to implicitly request all child LeafNodes
  • sorting is not appropiate nor doable
  • specify the top level structure of the search response in the protocol with a slot for metadata and one for the content defined as records. * allow the response of multiple "datasets" with different metadata from a single datasource to suit the needs of databases like fishbase and systax * allow the * allow the metadata definition to be chosen by the provider and make it a mandatory part of the reponse that cannot be altered by any request. Do so for all paging and subsequent responses to the same client.
• InventoryRequest
  • allow multiple concepts to be scanned
  • optionally request sorting of result list. order by sequence of requested concepts if multiple.
• ConceptualBindingProposalOne accepted. OK to use namespace declaration in xml manner. Concept identifier attribute is to be called "path".
• valid filter operators
  • Logical: AND, OR, NOT with AND + OR taking multiple arguments while NOT is unary.
  • Comparative: equals, lessThan, lessThanOrEquals, greaterThan, greaterThanOrEquals, like, in, isNull
  • There is no need for an isMapped operator.
• Filters
  • allow search requests without filters (affects both).
  • evaluate to false if concept is not mapped but compared.
  • always insert info/warn diagnostic if unmapped concept encountered in request.
• use common Error Codes and prefixes for classification of codes. To be specified in more detail.
• Using a single POST or GET parameter called "request" which contains either the XML message or an URL pointing to the XML message.

XQuery

The XqueryLanguage seems not appropiate for now, as not enough free tools are availbale and writing parsers on our own would be too much work and hard to confine.

OpenGIS? CQL etc.

• their filters are similar, more powerful in general, but are lacking some features:
• comparative operator IN is missing
• functions supported
• spatial operators supported
• real expressions supported in comparisons that can "use" arithmetic operations, functions, literals and concepts
• An InventoryRequest is missing

SOAP

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