arangosh> db.names.ensureIndex({ type: "skiplist", fields: [ "first" ] }); { "deduplicate" : true, "fields" : [ "first" ], "id" : "names/15314", "isNewlyCreated" : true, "sparse" : false, "type" : "skiplist", "unique" : false, "code" : 201 } arangosh> db.names.save({ "first" : "Tim" }); { "_id" : "names/15328", "_key" : "15328", "_rev" : "_VRerB5S---" } arangosh> db.names.save({ "first" : "Tom" }); { "_id" : "names/15332", "_key" : "15332", "_rev" : "_VRerB5S--_" } arangosh> db.names.save({ "first" : "John" }); { "_id" : "names/15335", "_key" : "15335", "_rev" : "_VRerB5S--A" } arangosh> db.names.save({ "first" : "Tim" }); { "_id" : "names/15338", "_key" : "15338", "_rev" : "_VRerB5W---" } arangosh> db.names.save({ "first" : "Tom" }); { "_id" : "names/15341", "_key" : "15341", "_rev" : "_VRerB5W--_" }