cypher - neo4j 密码查询太慢

Question

以下查询，需要 1.5 秒到 9 秒，取决于{关键字}

match (pr:Property)
WHERE (pr.name in {keywords})
with pr
MaTCH (pr) <--(it:Item)
MaTCH (it)-->(pr2)<-[:CAT]-(ca)
return distinct pr2 as prop,count(distinct it) as sum , ca.name as rType
limit 10

每个 Item 都连接到 100 个 Properties。

服务器上的示例配置文件:

neo4j-sh (?)$ profile match (pr:Property)
WHERE (pr.name in ["GREEN","SHORT","PLAIN","SHORT-SLEEVE"])
with pr
MaTCH (pr) <--(it:Item)
MaTCH (it)-->(pr2)<-[:CAT]-(ca)
return distinct pr2 as prop,count(distinct it) as sum , ca.name as rType
limit 40;
+------------------------------------------------------------------------------------------40 rows

ColumnFilter(symKeys=["prop", "rType", "  INTERNAL_AGGREGATE58d28d0e-5727-4850-81ef-7298d63d7be8"], returnItemNames=["prop", "sum", "rType"], _rows=40, _db_hits=0)
Slice(limit="Literal(40)", _rows=40, _db_hits=0)
  EagerAggregation(keys=["Cached(prop of type Node)", "Cached(rType of type Any)"], aggregates=["(  INTERNAL_AGGREGATE58d28d0e-5727-4850-81ef-7298d63d7be8,Distinct(Count(it),it))"], _rows=40, _db_hits=0)
    Extract(symKeys=["it", "ca", "  UNNAMED122", "pr", "pr2", "  UNNAMED130", "  UNNAMED99"], exprKeys=["prop", "rType"], _rows=645685, _db_hits=645685)
      SimplePatternMatcher(g="(it)-['  UNNAMED122']-(pr2),(ca)-['  UNNAMED130']-(pr2)", _rows=645685, _db_hits=0)
        Filter(pred="hasLabel(it:Item(0))", _rows=6258, _db_hits=0)
          SimplePatternMatcher(g="(it)-['  UNNAMED99']-(pr)", _rows=6258, _db_hits=0)
            Filter(pred="any(-_-INNER-_- in Collection(List(Literal(GREEN), Literal(SHORT), Literal(PLAIN), Literal(SHORT-SLEEVE))) where Property(pr,name(1)) == -_-INNER-_-)", _rows=4, _db_hits=1210)
              NodeByLabel(identifier="pr", _db_hits=0, _rows=304, label="Property", identifiers=["pr"], producer="NodeByLabel")

neo4j 版本:2.0.1

堆大小:最大 3.2 GB(离它还差得很远..)

数据库磁盘使用:270MB

节点数:4368

关系数:395693

计算机:AWS EC2 c3.large。 但是，尝试在快 4 倍的计算机上运行它，结果是一样的..

在查看 JConsole 时，我可以看到堆从 50mb 增加到 70mb，然后被 GC 清理。

无论如何让它更快？这种表现对我来说太慢了......

编辑: 正如建议的那样，我尝试组合匹配项，但正如您在配置文件中看到的那样，速度较慢:

neo4j-sh (?)$ profile match (pr:Property) WHERE (pr.name in ["GREEN","SHORT","PLAIN","SHORT-SLEEVE"]) with pr MaTCH (pr) <--(it:Item)-->(pr2)<-[:CAT]-(ca) return distinct pr2 as prop,count(distinct it) as sum , ca.name as rType limit 40;

ColumnFilter(symKeys=["prop", "rType", "  INTERNAL_AGGREGATEa6eaa53b-5cf4-4823-9e4d-0d1d66120d51"], returnItemNames=["prop", "sum", "rType"], _rows=40, _db_hits=0)
Slice(limit="Literal(40)", _rows=40, _db_hits=0)
  EagerAggregation(keys=["Cached(prop of type Node)", "Cached(rType of type Any)"], aggregates=["(  INTERNAL_AGGREGATEa6eaa53b-5cf4-4823-9e4d-0d1d66120d51,Distinct(Count(it),it))"], _rows=40, _db_hits=0)
    Extract(symKeys=["  UNNAMED111", "it", "ca", "  UNNAMED119", "pr", "pr2", "  UNNAMED99"], exprKeys=["prop", "rType"], _rows=639427, _db_hits=639427)
      Filter(pred="(hasLabel(it:Item(0)) AND hasLabel(it:Item(0)))", _rows=639427, _db_hits=0)
        SimplePatternMatcher(g="(ca)-['  UNNAMED119']-(pr2),(it)-['  UNNAMED99']-(pr),(it)-['  UNNAMED111']-(pr2)", _rows=639427, _db_hits=0)
          Filter(pred="any(-_-INNER-_- in Collection(List(Literal(GREEN), Literal(SHORT), Literal(PLAIN), Literal(SHORT-SLEEVE))) where Property(pr,name(1)) == -_-INNER-_-)", _rows=4, _db_hits=1210)
            NodeByLabel(identifier="pr", _db_hits=0, _rows=304, label="Property", identifiers=["pr"], producer="NodeByLabel")

Answer 1

首先，确保 Property 标签上的 name 属性已被索引。据我所知，索引不与 IN 语句一起使用，但这应该在未来的版本中解决。性能很快就会好起来。

CREATE INDEX ON :Property(name)

您可以按如下方式减少查询:

MATCH (pr:Property)
WHERE (pr.name in {keywords})
MATCH (pr)<--(it:Item)-->(pr2)<-[:CAT]-(ca)
RETURN distinct pr2 as prop,count(distinct it) as sum , ca.name as rType
LIMIT 10