arangosh> db.example.insert({"a" : { "one" : 1, "two" : 2, "three" : 3 }, ........> "b" : { }}); { "_id" : "example/20774804", "_key" : "20774804", "_rev" : "_VOyxnle---" } arangosh> db.example.update("example/20774803", {"a" : { "four" : 4 }, ........> "b" : { "b1" : 1 }}); { "_id" : "example/20774803", "_key" : "20774803", "_rev" : "_VOyxnle--_", "_oldRev" : "_VOyxnla---" } arangosh> db.example.document("example/20774803"); { "_key" : "20774803", "_id" : "example/20774803", "_rev" : "_VOyxnle--_", "b" : { "b1" : 1 }, "a" : { "four" : 4 } } arangosh> db.example.update("example/20774803", { "a" : { "one" : null }, ........> "b" : null }, ........> false, false); { "_id" : "example/20774803", "_key" : "20774803", "_rev" : "_VOyxnli---", "_oldRev" : "_VOyxnle--_" } arangosh> db.example.document("example/20774803"); { "_key" : "20774803", "_id" : "example/20774803", "_rev" : "_VOyxnli---", "a" : { "four" : 4 } }