在Neo4j中添加新节点时的查询性能

Question

我想知道为什么我的Cypher查询花费了过多的时间。

基本上，我有一个小的家族树（两个家庭），我正在尝试为每个家庭树添加一个带有一些小元数据的新节点，这样当他们家人更容易彼此隔离时被查询。 （感谢@Tim Kuehn为此advice）。

一旦我运行查询来填充我的两个家庭，我就有了这个，它很快就可以构建而没有问题：

接下来，我想创建上述新节点。第一个节点快速创建，应用于较小的系列（我称之为B系列）：

// 'add a :Family node for each relational group, like so:'

CREATE (famB:Family) 
WITH famB
MATCH (a:Person {name:"Gramps Johnson"})-[:RELATED_TO*]->(b:Person)  
MERGE (famB:Family)<-[:FAMILY]-(a) 
MERGE (famB:Family)<-[:FAMILY]-(b) 

......这给了我这个。到现在为止还挺好！

然而，向前发展，由于某种原因，从未创建过大的族节点。代码是相同的，但查询只是运行并运行...

// 'add a :Family node for each relational group, like so:'

CREATE (famA:Family) 
WITH famA
MATCH (a:Person {name:"Gramps Doe"})-[:RELATED_TO*]->(b:Person)  
MERGE (famA:Family)<-[:FAMILY]-(a) 
MERGE (famA:Family)<-[:FAMILY]-(b)

为什么会这样？

我的第一个想法是在name属性上添加一个索引：

// put index' on the name properties of the nodes:
// CREATE INDEX ON :Person(name)  

但是没有做任何事情。

所以我试着看一下EXPLAIN，但它并没有真正告诉我任何事情。 （它在执行时也会永久运行在终端上。）

感谢您的帮助。

这是我创建图表的代码：

// FAMILY A2: create grandparents, their son.

CREATE (grampsdoe:Person {name: 'Gramps Doe', id:'1', Gender:'Male', Diagnosis: 'Alzheimers', `Is Alive?`: 'No', Handedness: 'Left', `Risk Score`: 'PURPLE'})
CREATE (gramsdoe:Person {name: 'Grams Doe', id:'2', Gender:'Female', Diagnosis: 'Alzheimers', `Is Alive?`: 'No', Handedness: 'Right', `Risk Score`: 'GIRAFFE'})
CREATE (daddoe:Person {name: 'Dad Doe', id:'3', Gender:'Male', Diagnosis: 'MCI', `Is Alive?`: 'No', Handedness: 'Right', `Risk Score`: 'GIRAFFE'})

CREATE
(grampsdoe)-[:RELATED_TO {relationship: 'Husband'}]->(gramsdoe),
(gramsdoe)-[:RELATED_TO {relationship: 'Wife'}]->(grampsdoe),
(grampsdoe)-[:RELATED_TO {relationship: 'Father'}]->(daddoe),
(gramsdoe)-[:RELATED_TO {relationship: 'Mother'}]->(daddoe),
(daddoe)-[:RELATED_TO {relationship: 'Son'}]->(grampsdoe),
(daddoe)-[:RELATED_TO {relationship: 'Son'}]->(gramsdoe)


// FAMILY A2: create grandparents, their daughter

CREATE (grampssmith:Person {name: 'Gramps Smith', id:'4', Gender:'Male', Diagnosis: 'Normal', `Is Alive?`: 'No', Handedness: 'Left', `Risk Score`: 'PURPLE'})
CREATE (gramssmith:Person {name: 'Grams Smith', id:'5', Gender:'Female', Diagnosis: 'Alzheimers', `Is Alive?`: 'No', Handedness: 'Ambidextrous', `Risk Score`: 'PURPLE'})
CREATE (momsmith:Person {name: 'Mom Doe', id:'6', Gender:'Female', Diagnosis: 'Alzheimers', `Is Alive?`: 'No', Handedness: 'Right', `Risk Score`: 'GIRAFFE'})

CREATE
(grampssmith)-[:RELATED_TO {relationship: 'Husband'}]->(gramssmith),
(gramssmith)-[:RELATED_TO {relationship: 'Wife'}]->(grampssmith),
(grampssmith)-[:RELATED_TO {relationship: 'Father'}]->(momsmith),
(gramssmith)-[:RELATED_TO {relationship: 'Mother'}]->(momsmith),
(momsmith)-[:RELATED_TO {relationship: 'Daughter'}]->(grampssmith),
(momsmith)-[:RELATED_TO {relationship: 'Daughter'}]->(gramssmith)


// FAMILY A3: 'Dad Doe' and 'Mom Smith' get married and have 2 kids who are twins
CREATE (lilbro:Person {name: 'Lil Bro', id:'7', Gender:'Male', Diagnosis: 'Normal', `Is Alive?`: 'Yes', Handedness: 'Right', `Risk Score`: 'PURPLE'})
CREATE (bigsis:Person {name: 'Big Sis', id:'8', Gender:'Female', Diagnosis: 'Normal', `Is Alive?`: 'Yes', Handedness: 'Right', `Risk Score`: 'PURPLE'})

CREATE (daddoe)-[:RELATED_TO {relationship: 'Husband'}]->(momsmith)
CREATE (momsmith)-[:RELATED_TO {relationship: 'Wife'}]->(daddoe) 

CREATE (lilbro)-[:RELATED_TO {relationship: 'Brother'}]->(bigsis)

CREATE
(lilbro)-[:RELATED_TO {relationship: 'Grandson'}]->(grampsdoe),
(grampsdoe)-[:RELATED_TO {relationship: 'Grandfather'}]->(lilbro),
(lilbro)-[:RELATED_TO {relationship: 'Grandson'}]->(grampssmith),
(grampssmith)-[:RELATED_TO {relationship: 'Grandfather'}]->(lilbro),

(lilbro)-[:RELATED_TO {relationship: 'Grandson'}]->(grampssmith),
(grampssmith)-[:RELATED_TO {relationship: 'Grandmother'}]->(lilbro),
(lilbro)-[:RELATED_TO {relationship: 'Grandson'}]->(gramssmith),
(gramssmith)-[:RELATED_TO {relationship: 'Grandmother'}]->(lilbro),


(lilbro)-[:RELATED_TO {relationship: 'Son'}]->(daddoe),
(daddoe)-[:RELATED_TO {relationship: 'Father'}]->(lilbro),
(lilbro)-[:RELATED_TO {relationship: 'Son'}]->(momsmith),
(momsmith)-[:RELATED_TO {relationship: 'Mother'}]->(lilbro),

(bigsis)-[:RELATED_TO {relationship: 'Sister'}]->(lilbro),

(bigsis)-[:RELATED_TO {relationship: 'Granddaughter'}]->(grampsdoe),
(grampsdoe)-[:RELATED_TO {relationship: 'Grandfather'}]->(bigsis),
(bigsis)-[:RELATED_TO {relationship: 'Granddaughter'}]->(grampssmith),
(grampssmith)-[:RELATED_TO {relationship: 'Grandfather'}]->(bigsis),

(bigsis)-[:RELATED_TO {relationship: 'Granddaughter'}]->(gramsdoe),
(gramsdoe)-[:RELATED_TO {relationship: 'Grandmother'}]->(bigsis),
(bigsis)-[:RELATED_TO {relationship: 'Granddaughter'}]->(gramssmith),
(gramssmith)-[:RELATED_TO {relationship: 'Grandfather'}]->(bigsis),


(bigsis)-[:RELATED_TO {relationship: 'Daughter'}]->(daddoe),
(daddoe)-[:RELATED_TO {relationship: 'Father'}]->(bigsis),
(bigsis)-[:RELATED_TO {relationship: 'Daughter'}]->(momsmith),
(momsmith)-[:RELATED_TO {relationship: 'Mother'}]->(bigsis)



// FAMILY B1: create grandparents, their son.

CREATE (grampsjohnson:Person {name: 'Gramps Johnson', id:'9', Gender:'Male', Diagnosis: 'Normal', `Is Alive?`: 'No', Handedness: 'Right', `Risk Score`: 'GIRAFFE'})
CREATE (gramsjohnson:Person {name: 'Grams Johnson', id:'10', Gender:'Female', Diagnosis: 'Normal', `Is Alive?`: 'No', Handedness: 'Right', `Risk Score`: 'GIRAFFE'})
CREATE (johnjohnson:Person {name: 'John Johnson', id:'11', Gender:'Male', Diagnosis: 'MCI', `Is Alive?`: 'Yes', Handedness: 'Right', `Risk Score`: 'GIRAFFE'})

CREATE
(grampsjohnson)-[:RELATED_TO {relationship: 'Husband'}]->(gramsjohnson),
(gramsjohnson)-[:RELATED_TO {relationship: 'Wife'}]->(grampsjohnson),
(grampsjohnson)-[:RELATED_TO {relationship: 'Father'}]->(johnjohnson),
(gramsjohnson)-[:RELATED_TO {relationship: 'Mother'}]->(johnjohnson),
(johnjohnson)-[:RELATED_TO {relationship: 'Son'}]->(grampsjohnson),
(johnjohnson)-[:RELATED_TO {relationship: 'Son'}]->(gramsjohnson)

Answer 1

  

为什么会发生这种情况？

正在发生的原因是第二个家庭不再是一个循环，它是“每个人都连接两次”。这意味着“制作一个家庭节点”代码的这一部分：

MATCH (a:Person {name:"Gramps Doe"})-[:RELATED_TO*]->(b:Person)  

正在追踪大量图表，因此系统停滞不前。

由于目标组中有8个节点，我将路径限制在1到8跳的范围内（ [：RELATED_TO * 1..8] ） -

CREATE (famA:Family) 
WITH famA
MATCH (a:Person {name:"Gramps Doe"})-[:RELATED_TO*1..8]->(b:Person)  
MERGE (famA:Family)<-[:FAMILY]-(a) 
MERGE (famA:Family)<-[:FAMILY]-(b)

然后就完成了。

让疾病已经出现一定次数的整个家庭：

// count the family members with a disease
MATCH (f:Family)<-[:FAMILY]-(person:Person) 
WHERE person.Diagnosis = "Alzheimers" 
WITH f, count(person) AS Count 
WHERE Count > 2 

// Then report the family members as a single collection
MATCH (a:Person)-[r1:FAMILY]-(f)
RETURN collect(DISTINCT a)