SPARQL and SOAP.

Hello,

I confirm that both current version of Virtuoso Universal server 5.0 and latest publicly available release of Virtuoso Open Source support SOAP requests to SPARQL web service endpoint.
The endpoints supports HTTP GET, HTTP POST and SOAP 1.2. The implementation is backward-compatible with the spec for HTTP GET and HTTP POST: parameters listed in spec are all supported plus there are optional implementation-specific parameters as well.
SOAP 1.2 recognizes only 'default-graph-uri', 'named-graph-uri' and, of course, 'query'. (Should support at least 'maxrows' in addition to these three.)

We have support for SOAP1.2 but not about WSDL 2.0, this means we can only compose proper responses for proper application/soap+xml requests but "we can't import WSDL into a wrappers nor we can
generate automatically WSDL from a SP" as reported by Mitko Iliev who knows WSDL (unlike me).

We have known internationalization issue in SPARQL but SOAP matches the requirement of spec re. UTF-8.

Hence I believe that Virtuoso (both commercial and free) is a "conformant SPARQL Protocol service". Requirements are:

"must implement the SparqlQuery interface;" -- yes.

"may implement HTTP, SOAP, or both HTTP and SOAP bindings of the query operation of the SparqlQuery interface;" -- yes, both are implemented

"must implement HTTP or SOAP bindings of query in the way described in this document ("SPARQL Protocol for RDF"), in sparql-protocol-query.wsdl, and sparql-protocol-types.xsd;" -- yes

"may implement other interfaces, bindings of the operations of those interfaces, or bindings of the query operation other than the normative HTTP or SOAP bindings described by SPARQL Protocol for RDF;" -- of course :)

"must be consistent with the normative constraints (indicated by [RFC 2119] keywords) described in 3. Policy Considerations." -- to some degree; we have built-in safety checks to try avoiding DOS attacks but unhappy query can block the server, no doubt.


Best Regards,
Ivan Mikhailov.

Received on Wednesday, 29 August 2007 13:31:15 UTC