arangosh> db.example.insert({"a" : { "one" : 1, "two" : 2, "three" : 3 }, ........> "b" : { }}); { "_id" : "example/15709", "_key" : "15709", "_rev" : "15709" } arangosh> db.example.update("example/20774803", {"a" : { "four" : 4 }, ........> "b" : { "b1" : 1 }}); { "_id" : "example/20774803", "_key" : "20774803", "_oldRev" : "15705", "_rev" : "15712" } arangosh> db.example.document("example/20774803"); { "_id" : "example/20774803", "_key" : "20774803", "_rev" : "15712", "a" : { "four" : 4 }, "b" : { "b1" : 1 } } arangosh> db.example.update("example/20774803", { "a" : { "one" : null }, ........> "b" : null }, ........> false, false); { "_id" : "example/20774803", "_key" : "20774803", "_oldRev" : "15712", "_rev" : "15716" } arangosh> db.example.document("example/20774803"); { "_id" : "example/20774803", "_key" : "20774803", "_rev" : "15716", "a" : { "four" : 4 } }