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If an RDF Dataset is not specified in either the protocol request or the SPARQL query string, then implementations may execute the query against an implementation-defined default RDF dataset.
Motivation
In MMS5Flexo MMS, the graph IRI for each materialized snapshot is an opaque, non-human-readable identifier. Advanced query authors have the ability to query for these graph IRIs and use arbitrary constraints to filter which model(s) get evaluated. For example, to query for a specific graph pattern among any snapshots that materialize commits made in January of 2021:
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Denying such requests with a 400 response is the preferred option for virtual endpoints since their primary purpose is to scope (and contextualize) SPARQL queries to a specific named graph. Instead, SPARQL queries that rely on the use named graphs should be directed to the global, ‘non-virtual’ MMS5 Flexo MMS endpoint.
Virtual endpoint REST API
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