JanusGraph实战笔记·数据写入·查询

mgmt = graph.openManagement()
nameProperty = mgmt.makePropertyKey("names").dataType(String.class).cardinality(Cardinality.SET).make() #加上.cardinality(Cardinality.SET)表示names的类型有String变为Set<String>吗？
mgmt.buildIndex("search", Vertex.class).addKey(nameProperty, Mapping.STRING.asParameter()).buildMixedIndex("search")
mgmt.commit()
//Insert a vertex
person = graph.addVertex()
person.property("names", "Robert")
person.property("names", "Bob")
graph.tx().commit()
//Now query it
g.V().has("names", "Bob").count().next() //1
g.V().has("names", "Robert").count().next() //1

- 配置文件中强制开启索引，不然就会不使用索引
-  force-index =true

    -  这不是表示必须要使用索引吗？ 不是“”“不然就不会使用索引”的意思吧

-  Composite Index

    -   Composite indexes are very fast and efficient but limited to equality lookups for a particular, previously-defined combination of property keys.

-  Mixed Index

    -  Mixed indexes can be used for lookups on any combination of indexed keys and support multiple condition predicates in addition to equality depending on the backing index store.

g.V().has("name", "hercules")
// 2) Find all vertices with an age greater than 50
g.V().has("age", gt(50))
// or find all vertices between 1000 (inclusive) and 5000 (exclusive) years of age and order by increasing age
g.V().has("age", inside(1000, 5000)).order().by("age", incr)
// which returns the same result set as the following query but in reverse order
g.V().has("age", inside(1000, 5000)).order().by("age", decr)
// 3) Find all edges where the place is at most 50 kilometers from the given latitude-longitude pair
g.E().has("place", geoWithin(Geoshape.circle(37.97, 23.72, 50)))
// 4) Find all edges where reason contains the word "loves"
g.E().has("reason", textContains("loves"))
// or all edges which contain two words (need to chunk into individual words)
g.E().has("reason", textContains("loves")).has("reason", textContains("breezes"))
// or all edges which contain words that start with "lov"
g.E().has("reason", textContainsPrefix("lov"))
// or all edges which contain words that match the regular expression "br[ez]*s" in their entirety
g.E().has("reason", textContainsRegex("br[ez]*s"))
// or all edges which contain words similar to "love"
g.E().has("reason", textContainsFuzzy("love"))
// 5) Find all vertices older than a thousand years and named "saturn"
g.V().has("age", gt(1000)).has("name", "saturn")

  GraphTraversalSource g = graph.traversal();

        LinkedList<Long> times = new LinkedList<Long>();
        long time;
        Instant inst1;
        Instant inst2;

        //Query 1
        inst1 = Instant.now();
        List<Vertex> ret1 = g.V().has("type_object_type", "geography_mountain").toList();
        inst2 = Instant.now();
        time = Duration.between(inst1, inst2).toMillis();
        times.add(time);
        System.out.println("Query 1 used " + time + " ms. And query1 returns " + ret1.size() + " records.");

        //Query 2
        inst1 = Instant.now();
        List<Vertex> ret2 = g.V().has("type_object_name", "\"美国\"").toList();
        System.out.println("美国的records为" + ret2.size());
        inst2 = Instant.now();
        time = Duration.between(inst1, inst2).toMillis();
        times.add(time);
        System.out.println("Query 2 used " + time + " ms. And query2 returns " + ret2.size() + " records.");

        //Query 3
        inst1 = Instant.now();
        List<Vertex> ret3 = g.V().has("type_object_type", "geography_mountain")
                .has("geography_mountain_elevation", P.gt(1000)).toList();
        inst2 = Instant.now();
        time = Duration.between(inst1, inst2).toMillis();
        times.add(time);
        System.out.println("Query 3 used " + time + " ms. And query3 returns " + ret3.size() + " records.");

        //Query 4
        inst1 = Instant.now();

        List<Object> ret4 = g.V().has("type_object_type", "geography_mountain").order().values("type_object_name").toList();

        inst2 = Instant.now();
        time = Duration.between(inst1,inst2).toMillis();
        times.add(time);
        System.out.println("Query 4 used " + time + " ms. And query3 returns " + ret4.size() + " records.");

        //Query 5
        inst1 = Instant.now();
        List<Object> ret5 = g.V().has("name", "<http://knowledge.microsoft.com/5232ed96-85b1-2edb-12c6-63e6c597a1de>")
                .out("location_location_administrative_capital").has("type_object_alias").values("type_object_alias").toList();
        inst2 = Instant.now();
        time = Duration.between(inst1, inst2).toMillis();
        times.add(time);
        System.out.println("Query 5 used " + time + " ms. And query3 returns " + ret5.size() + " records.");

        //Query 6
        inst1 = Instant.now();
        List<Object> ret6 = g.V().has("type_object_type", "location_city").out("location_location_contained_by").
                out("location_location_contained_by").out("location_location_contained_by").
                values("location_location_area").limit(100)
                .toList();
        inst2 = Instant.now();
        time = Duration.between(inst1, inst2).toMillis();
        times.add(time);
        System.out.println("Query 6 used " + time + " ms. And query6 returns " + ret6.size() + " records.");


        return times;