arangosh> db.ids.ensureIndex({ type: "persistent", fields: [ "name.first", "name.last" ], unique: true }); { "id" : "ids/15197", "type" : "persistent", "fields" : [ "name.first", "name.last" ], "unique" : true, "sparse" : false, "isNewlyCreated" : true, "code" : 201 } arangosh> db.ids.save({ "name" : { "first" : "hans", "last": "hansen" }}); { "_id" : "ids/15200", "_key" : "15200", "_rev" : "_U-_q2xO---" } arangosh> db.ids.save({ "name" : { "first" : "jens", "last": "jensen" }}); { "_id" : "ids/15204", "_key" : "15204", "_rev" : "_U-_q2xO--_" } arangosh> db.ids.save({ "name" : { "first" : "hans", "last": "jensen" }}); { "_id" : "ids/15207", "_key" : "15207", "_rev" : "_U-_q2xS---" } arangosh> db.ids.save({ "name" : { "first" : "hans", "last": "hansen" }}); [ArangoError 1210: cannot create document, unique constraint violated]