Which is quicker - INTERSECT or just subquery?

[ASmee]

Which of these two would be the most efficient, and how do I ascertain this info:

delete from riskvarhistory where histjobid in (select histjobid from riskvarhistory INTERSECT select id from histvarjob@my_prim);

or

DELETE FROM RiskVarHistory WHERE histjobid in (select ID FROM histvarjob@my_prim);

Where @my_prim is a public database link.