Amazon Neptune
User Guide (API Version 2017-11-29)

Specifying a Named Graph for Load

Amazon Neptune associates every triple with a named graph. If you don't specify a named graph when loading, inserting, or updating triples, Neptune uses the fallback named graph defined by the URI

You can specify the named graph to use for all triples (or quads with the fourth position blank) by using the parserConfiguration: namedGraphUri parameter. For information about the Load command syntax, see Neptune Loader Command.