如何优化高尺寸图的neo4j密码查询？

如何解决如何优化高尺寸图的neo4j密码查询？

我编写此查询是为了查找两个节点之间的可能路径。但是，当我尝试使用超过 3 个步骤时，它无法完成工作。我使用的图表包含超过 400 万个节点和 4900 万个关系。

match (src:T047 {CUI:"C0030920"}),(trg:T059 {CUI:"C1294944"}),p = (src)-[*..3]-(trg)
where 
      all(relI in relationships(p) 
      where type(relI) in ["RO","CHD","PAR","RB","RL","RO","SIB","RU","SY"])
and
      all(nodeI in nodes(p)
      where labels(nodeI) in ["T004","T005","T007","T016","T017","T018","T019","T020","T021","T022","T023","T024","T025","T026","T028","T029","T030","T031","T032","T033","T034","T037","T038","T039","T040","T041","T042","T043","T045","T046","T047","T048","T049","T053","T054","T055","T056","T057","T059","T060","T061","T074","T080","T081","T098","T099","T100","T101","T103","T109","T114","T116","T121","T123","T125","T126","T127","T129","T131","T168","T184","T190","T191","T195","T196","T197","T200","T201"])
return p

这是此查询的计划： https://imgur.com/PpWePOz

是否有任何可能的方法来优化此查询或至少找到估计时间？

解决方法

首先，您的查询计划显示您没有使用索引，因此它对 :T059 节点使用 NodeByLabelScan 并在所有节点上运行过滤器以查找具有相关属性的那些。 src 节点也不使用索引查找，而是针对标签和属性过滤可变长度扩展的结果。

您将需要这些索引来帮助提高性能。 :T047(CUI) 和 :T059(CUI) 上的索引是您在此处需要的索引。确保你先拥有这个。

此外，为了强制索引查找（与 var-length-expand 和过滤器相反，后者会更昂贵），您可以向规划器提供索引提示。

我们还可以调整路径中节点标签的列表谓词，以便它们在扩展期间而不是之后被过滤。

WITH ["T004","T005","T007","T016","T017","T018","T019","T020","T021","T022","T023","T024","T025","T026","T028","T029","T030","T031","T032","T033","T034","T037","T038","T039","T040","T041","T042","T043","T045","T046","T047","T048","T049","T053","T054","T055","T056","T057","T059","T060","T061","T074","T080","T081","T098","T099","T100","T101","T103","T109","T114","T116","T121","T123","T125","T126","T127","T129","T131","T168","T184","T190","T191","T195","T196","T197","T200","T201"] as allowedLabels
MATCH (src:T047 {CUI:"C0030920"}),(trg:T059 {CUI:"C1294944"})
USING INDEX src:T047(CUI)
USING INDEX trg:T059(CUI)
MATCH p = (src)-[*..3]-(trg)
WHERE 
      all(relI in relationships(p) WHERE type(relI) in ["RO","CHD","PAR","RB","RL","RO","SIB","RU","SY"])
    AND all(node IN nodes(p) WHERE labels(node)[0] IN allowedLabels)
RETURN p

这也假设这里的所有节点只有一个可能的标签，而不是多个。如果它们可以有多个标签，那么我们可能需要重构查询。