Get the name of the target Relation from Query struct?

Hello,

I want to get the target Relation name for a UPDATE / INSERT / DELETE in a planner_hook. Do I understand struct Query
correctlythat: 

Query->resultRelation will be the index into Query->rtable to give me the target Relation?

And if yes, what would rtable give me as list entry? An OID or a Relation or something else?

Best regards,

Ernst-Georg