arangosh> db.test.ensureIndex({ type: "skiplist", fields: [ "a[*]" ] }); { "id" : "test/15164", "type" : "skiplist", "fields" : [ "a[*]" ], "unique" : false, "sparse" : false, "isNewlyCreated" : true, "code" : 201 } arangosh> db.test.save({ a : [ 1, 2 ] }); { "_id" : "test/15167", "_key" : "15167", "_rev" : "_U-_q2v2---" } arangosh> db.test.save({ a : [ 1, 3 ] }); { "_id" : "test/15171", "_key" : "15171", "_rev" : "_U-_q2v2--_" } arangosh> db.test.save({ a : null }); { "_id" : "test/15174", "_key" : "15174", "_rev" : "_U-_q2v6---" }