arangosh> db.test.ensureIndex({ type: "skiplist", fields: [ "a[*]" ] }); { "id" : "test/15343", "type" : "skiplist", "fields" : [ "a[*]" ], "unique" : false, "sparse" : false, "isNewlyCreated" : true, "code" : 201 } arangosh> db.test.save({ a : [ 1, 2 ] }); { "_id" : "test/15346", "_key" : "15346", "_rev" : "_V_qEhhS---" } arangosh> db.test.save({ a : [ 1, 3 ] }); { "_id" : "test/15350", "_key" : "15350", "_rev" : "_V_qEhhW---" } arangosh> db.test.save({ a : null }); { "_id" : "test/15353", "_key" : "15353", "_rev" : "_V_qEhha---" }