前言

图分析是数据科学中的一个重要领域，其专注于通过图结构来表示数据，并执行各种计算和分析任务。图结构由节点（或称为顶点）和边组成，节点通常代表实体，边表示实体之间的关系。图计算广泛应用于社交网络分析、推荐系统、知识图谱、路径优化等多个领域。

PolarDB PostgreSQL版（下文简称为 PolarDB）是一款阿里云自主研发的云原生关系型数据库产品，100% 兼容 PostgreSQL，高度兼容Oracle语法（公有云版支持Oracle语法）；采用基于 Shared-Storage 的存储计算分离架构，具有极致弹性、毫秒级延迟、HTAP 的能力和高可靠、高可用、弹性扩展等企业级数据库特性。同时，PolarDB 具有大规模并行计算能力，可以应对OLTP与OLAP混合负载。

本文介绍的图分析能力，依托阿里云云原生关系型数据库PolarDB PostgreSQL版建设输出。

业务场景

背景信息

保险理赔欺诈一般根据保险提供商所具备的患者、疾病和索赔等数据，分析与被保人相关的理赔单、疾病等实体的关联关系，识别异常理赔记录，发现欺诈团伙。

数据和模型

数据来源自以保险领域公开数据集。

数据包括保险行业基本元素，可以将数据模型抽象为下图：

点：投保人（policyholder）、保单（incharge）、理赔（claim）、病人（patient）、疾病（disease）。
边：疾病-病人（has_disease）、投保人-理赔（policyholder_of_claim）、保单-理赔（inchagre_of_claim）、病人-理赔（insured_of_claim）、相似理赔（similar_claim）、投保人关联（policyholder_connection）。
属性：姓名（name），是否高危（high_risk）、风险分数（risk_score）、疾病名称（disease_name）、相似度（similarity_score）、关联等级（level）、理赔时间（claim_date）、保额（charge）等。

部分数据如下所示：

POLICYHOLDER（投保人）

"POLICYHOLDER_ID","FNAME","LNAME","RISK_SCORE","HIGH_RISK"
PH3068,ADAM,OCHSENBEIN,88,1
PH3069,MALINDA,MEHSERLE,42,0
PH3070,SANDRA,KUHTA,20,0
PH3071,DORA,TAHU,62,1
...

CLAIM（理赔）

"CLAIM_ID","CHARGE","CLAIM_DATE","DURATION","INSURED_ID","DIAGNOSIS","PERSON_INCHARGE_ID","TYPE","POLICYHOLDER_ID"
C3571,6517.53,2013-08-11 00:00:00,13,"28523",no exception,PI23070,services,PH9507     
C3572,49273.65,2017-02-10 00:00:00,3,"1220",no exception,PI21197,services,PH406      
C3573,52005.98,2014-06-29 00:00:00,27,"23735",no exception,PI22361,services,PH7911

POLICYHOLDER 和 CLAIM的关联关系

"CLAIM_ID","POLICYHOLDER_ID"
C1528,PH2963
C1529,PH1353
C1530,PH1071

最佳实践

技术实现

PolarDB 图数据库引擎 AGE(A Graph Extension) 是一个为 PostgreSQL系列数据库打造的扩展，旨在增强其处理图数据的能力。AGE 旨在结合关系型数据库与图数据库的优势，提供一个高性能、灵活且易于扩展的解决方案。

AGE主要包含以下特点

完全兼容PostgreSQL

AGE 是PolarDB PostgreSQL版的一个扩展，这意味着可以在现有的PolarDB数据库中使用，而无需重新构建数据库。AGE 继承了 PolarDB 的所有强大功能，包括事务、并发控制、以及多种索引和优化技术。

统一的图形和关系型查询

AGE 允许同时处理关系型数据和图形数据，可以在同一个查询中混合使用 SQL 和图查询语言。这使得处理复杂的数据模型更加容易和高效。

支持 Cypher 查询语言

AGE 支持使用 Cypher 查询语言，这是一种专为图数据库设计的查询语言，语法简单且灵活。为用户提供了一种直观的方式来进行图数据的查询和操作。

高性能

通过结合 PolarDB 的优化技术和专为图数据设计的索引，AGE 能够高效地处理大规模图形数据和复杂的图形查询。

如上所述，借助于AGE强大的能力，PolarDB可以简单、高效地处理各类图查询。

建议配置

为了得到良好的体验，建议使用以下配置：

项目	推荐配置
PolarDB 版本	标准版兼容PostgreSQL 14
CPU	>16 Core
内存	>64 GB
磁盘	>100GB (AUTOPL)
版本	>2.0.14.23.1

数据库准备

数据库中需要预先创建age扩展

create extension age;

在每个会话执行时，需要设置search_path并执行SQL来加载扩展：

SET search_path = ag_catalog, "$user", public;
select * from  get_cypher_keywords() limit 0;

如不想在每个会话中设置search_path，可对数据库进行该项操作

ALTER DATABASE xxx
SET search_path = ag_catalog, "$user", public;

数据入库

创建图

使用函数create_graph 可以创建一个图，创建时需要指定图的名称。

SELECT create_graph('graph');

插入节点和边

由于下载的数据为csv文件，不包含所需的id信息，因此需要将数据进行转换后进行入库操作。

本文附录中提供了将数据转换为PolarDB中vertex和edge的的python脚本，转换后如下所示：

POLICYHOLDER（投保人）

SELECT create_vlabel('graph','policyholder');
SELECT * FROM cypher('graph', $$ CREATE (:policyholder {policyholder_id:'PH3068',fname:'ADAM',lname:'OCHSENBEIN',risk_score:'88',high_risk:'1'}) $$ ) as (n agtype);
SELECT * FROM cypher('graph', $$ CREATE (:policyholder {policyholder_id:'PH3069',fname:'MALINDA',lname:'MEHSERLE',risk_score:'42',high_risk:'0'}) $$ ) as (n agtype);
SELECT * FROM cypher('graph', $$ CREATE (:policyholder {policyholder_id:'PH3070',fname:'SANDRA',lname:'KUHTA',risk_score:'20',high_risk:'0'}) $$ ) as (n agtype);
...

CLAIM（理赔）

- Create vlabel
SELECT create_vlabel('graph','claim');
SELECT * FROM cypher('graph', $$ CREATE (:claim {claim_id:'C3571',charge:'6517.53',claim_date:'2013-08-11 00:00:00',duration:'13',insured_id:'28523',diagnosis:'no exception',person_incharge_id:'PI23070',type:'services',policyholder_id:'PH9507'}) $$ ) as (n agtype);
SELECT * FROM cypher('graph', $$ CREATE (:claim {claim_id:'C3572',charge:'49273.65',claim_date:'2017-02-10 00:00:00',duration:'3',insured_id:'1220',diagnosis:'no exception',person_incharge_id:'PI21197',type:'services',policyholder_id:'PH406'}) $$ ) as (n agtype);
SELECT * FROM cypher('graph', $$ CREATE (:claim {claim_id:'C3573',charge:'52005.98',claim_date:'2014-06-29 00:00:00',duration:'27',insured_id:'23735',diagnosis:'no exception',person_incharge_id:'PI22361',type:'services',policyholder_id:'PH7911'}) $$ ) as (n agtype);
...

POLICYHOLDER 和 CLAIM的关联关系

SELECT * FROM cypher('graph', $$ MATCH (a:claim), (b:policyholder) WHERE a.claim_id = 'C1528' AND b.policyholder_id = 'PH2963' CREATE (a)-[e:RELTYPE  ]->(b) RETURN e$$) as (e agtype);
SELECT * FROM cypher('graph', $$ MATCH (a:claim), (b:policyholder) WHERE a.claim_id = 'C1529' AND b.policyholder_id = 'PH1353' CREATE (a)-[e:RELTYPE  ]->(b) RETURN e$$) as (e agtype);
SELECT * FROM cypher('graph', $$ MATCH (a:claim), (b:policyholder) WHERE a.claim_id = 'C1530' AND b.policyholder_id = 'PH1071' CREATE (a)-[e:RELTYPE  ]->(b) RETURN e$$) as (e agtype);
SELECT * FROM cypher('graph', $$ MATCH (a:claim), (b:policyholder) WHERE a.claim_id = 'C1531' AND b.policyholder_id = 'PH8102' CREATE (a)-[e:RELTYPE  ]->(b) RETURN e$$) as (e agtype);
SELECT * FROM cypher('graph', $$ MATCH (a:claim), (b:policyholder) WHERE a.claim_id = 'C1532' AND b.policyholder_id = 'PH4768' CREATE (a)-[e:RELTYPE  ]->(b) RETURN e$$) as (e agtype);
...

将转换后的结果保存为sql文件，配合客户端工具，如psql等可完成数据导入。

使用示例

简单查询

数据统计

各种类型节点数量

SELECT count(*) FROM cypher('graph', $$
MATCH (v)
RETURN v
$$) as (v agtype);
 count  
--------
 120567
   
-- claim
SELECT count(*) FROM cypher('graph', $$
MATCH (v:claim)
RETURN v
$$) as (v agtype);
 count  
--------
 100001
-- policyholder
SELECT count(*) FROM cypher('graph', $$
MATCH (v:policyholder)
RETURN v
$$) as (v agtype);
 count 
-------
 10006
-- incharge
SELECT count(*) FROM cypher('graph', $$
MATCH (v:incharge)
RETURN v
$$) as (v agtype);
 count 
-------
 10001
--disease
SELECT count(*) FROM cypher('graph', $$
MATCH (v:disease)
RETURN v
$$) as (v agtype);
count 
-------
   393
  
--patient
SELECT count(*) FROM cypher('graph', $$
MATCH (v:patient)
RETURN v
$$) as (v agtype);
 count 
-------
   166

过滤查询、排序查询

查询理赔单C4377的投保、理赔、被保情况

SELECT 'policyholder_id' as type, policyholder_id FROM cypher('graph', $$
MATCH (:claim {claim_id: 'C4377'})-[]->(policyholder:policyholder)
RETURN policyholder.policyholder_id
$$) as (policyholder_id agtype)
UNION
SELECT 'incharge_id', incharge_id FROM cypher('graph', $$
MATCH (:claim {claim_id: 'C4377'})-[]->(v:incharge)
RETURN v.incharge_id
$$) as (incharge_id agtype)
UNION
SELECT 'patient_id', patient_id FROM cypher('graph', $$
MATCH (:claim {claim_id: 'C4377'})-[]->(v:patient)
RETURN v.patient_id
$$) as (patient_id agtype);
      type       | policyholder_id 
-----------------+-----------------
 patient_id      | "11279"
 policyholder_id | "PH3759"
 incharge_id     | "PI26607"

通用场景

K阶邻居

已知保单C4377为欺诈保单，查询和理赔单C4377有相同理赔病人的理赔单，说明该理赔人有涉嫌骗保的嫌疑。

SELECT 'claim_id', claim_id FROM cypher('graph', $$
MATCH (:claim {claim_id: 'C4377'})-[]->(p:patient)<-[]-(c:claim)
RETURN c.claim_id
$$) as (claim_id agtype);
 ?column? | claim_id 
----------+----------
 claim_id | "C28963"
 claim_id | "C3679"
 claim_id | "C96545"
 claim_id | "C26586"
 claim_id | "C26754"
 claim_id | "C87278"
 claim_id | "C87603"
 claim_id | "C69395"
 claim_id | "C67594"
 claim_id | "C96155"
 claim_id | "C10160"

查询已知欺诈保单C4377的投保人的社交关系，可以对这些人的理赔情况提前预警。

SELECT 'policyholder_id', policyholder_id FROM cypher('graph', $$
MATCH (:claim {claim_id: 'C4377'})-[]->(a:policyholder)-[r*1..3]->(p:policyholder)
RETURN p.policyholder_id
$$) as (policyholder_id agtype);
    ?column?     | policyholder_id 
-----------------+-----------------
 policyholder_id | "PH52532"
 policyholder_id | "PH11283"
 policyholder_id | "PH11328"
 policyholder_id | "PH1"
 policyholder_id | "PH5"
 policyholder_id | "PH512"
 policyholder_id | "PH1569"
 policyholder_id | "PH4722"
 policyholder_id | "PH4731"

路径检索

查询投保人PH3759和投保人PH4722的路径，分析投保人之间的关联关系。

SELECT *
FROM cypher('graph', $$                        
    MATCH path = (:policyholder {policyholder_id: 'PH3759'})-[r*1..3]->(:policyholder {policyholder_id: 'PH4722'})
    RETURN path
$$) AS (v agtype);
-------
 [{"id": 844424930136988, "label": "policyholder", "properties": {"fname": "KURTIS", "lname": "ALKEMA", "high_risk": "1", "risk_score": "78", "policyholder_id": "PH3759"}}::vertex, {"id": 2251799813685487, "label": "RELTYPE", "end_id": 844424930133473, "start_id": 844424930136988, "properties": {"level": "65"}}::edge, {"id": 844424930133473, "label": "policyholder", "properties": {"fname": "TERRA", "lname": "SWARB", "high_risk": "0", "risk_score": "25", "policyholder_id": "PH512"}}::vertex, {"id": 2251799813685546, "label": "RELTYPE", "end_id": 844424930138502, "start_id": 844424930133473, "properties": {"level": "62"}}::edge, {"id": 844424930138502, "label": "policyholder", "properties": {"fname": "VETA", "lname": "SEDLACK", "high_risk": "0", "risk_score": "31", "policyholder_id": "PH1569"}}::vertex, {"id": 2251799813685594, "label": "RELTYPE", "end_id": 844424930136281, "start_id": 844424930138502, "properties": {"level": "92"}}::edge, {"id": 844424930136281, "label": "policyholder", "properties": {"fname": "DEANNA", "lname": "BALSER", "high_risk": "0", "risk_score": "36", "policyholder_id": "PH4722"}}::vertex]::path

共同邻居

查询保单C4377和保单C67594的共同邻居，从而找到两个保单的共同投保人。

SELECT 'policyholder_id', policyholder_id FROM cypher('graph', $$
MATCH (:claim {claim_id: 'C4377'})-[]->(p:policyholder)<-[]-(:claim  {claim_id: 'C67594'})
RETURN p.policyholder_id
$$) as (policyholder_id agtype);
    ?column?     | policyholder_id 
-----------------+-----------------
 policyholder_id | "PH3759"

协同推荐

已知保单C4377为欺诈保单，查找和保单C4377有共同投保人的保单，从而找到欺诈疑似涉诈保单。

SELECT 'claim_id', claim_id FROM cypher('graph', $$
MATCH (:claim {claim_id: 'C4377'})-[]->(p:policyholder)<-[]-(c:claim)
RETURN c.claim_id
$$) as (claim_id agtype);
?column? | claim_id 
----------+----------
 claim_id | "C28963"
 claim_id | "C96545"
 claim_id | "C3679"
 claim_id | "C87603"
 claim_id | "C26754"
 claim_id | "C26586"
 claim_id | "C87278"
 claim_id | "C69395"
 claim_id | "C67594"
 claim_id | "C96155"
 claim_id | "C10160"

与已知涉诈保单 C4377 相似度最大的保单，返回前20个：

with t as (
SELECT claim_id, replace(trim(both '"' from to_jsonb(properties)::text), '\"', '"') as similarity FROM cypher('graph', $$
MATCH (:claim {claim_id: 'C4377'})-[e]->(c:claim)
RETURN properties(e), c.claim_id
$$) as (properties agtype, claim_id agtype)
)
SELECT claim_id, replace((similarity::jsonb->'similarity_score')::text, '"','')::integer as s 
from t
ORDER BY s DESC
LIMIT 20;
claim_id | s  
----------+----
 "C67594" | 13
 "C69395" | 13
 "C10160" | 13
 "C87603" | 13
 "C28963" | 13
 "C3679"  | 13
 "C26754" | 13
 "C96155" | 13
 "C26586" | 13
 "C87278" | 13
 "C96545" | 13
 "C20113" |  8
 "C70759" |  8
 "C28785" |  8
 "C12793" |  8
 "C59736" |  8
 "C38059" |  8
 "C34068" |  8
 "C71827" |  8
 "C15760" |  8

总结

本文介绍了如何利用阿里云云原生关系型数据库PolarDB PostgreSQL版的图分析能力来进行图数据分析。

PolarDB结合AGE扩展，提供了图数据计算分析的功能，包括使用Cypher查询语言，高效处理查询图数据。本文以公开的保险数据集为例，示例了在保险理赔场景下，执行图查询来发现异常理赔记录和欺诈团伙：例如，查询与欺诈保单有相同理赔病人的其他保单，或者找出欺诈保单的投保人社交关系，以便进行欺诈预警。PolarDB在关系型数据库的基础上，提供了图分析能力，为企业的统一数据管理和分析，提供了强有力的支撑。

试用体验

欢迎访问PolarDB免费试用页面，选择试用“云原生数据库PolarDB PostgreSQL版”，体验PolarDB的图计算能力

附录

数据转换脚本

import csv
import os
def convert_vertex_csv(file_path, graph):
    file_name = os.path.splitext(os.path.basename(file_path))[0].lower()
    
    # create vlabel
    print("------------------------------------------------")
    print("-- Create vlabel")
    print("SELECT create_vlabel('{}','{}');".format(graph, file_name))
    with open(file_path, 'r') as csvfile:
        reader = csv.reader(csvfile, delimiter=',')
        header = next(reader)
        for row in reader:
            p = ""
            for h in header:
                if p != "":
                    p += ","
                else:
                    p += "{"
                p += "{}:'{}'".format(h.lower(), row[header.index(h)].strip())
            if p != "":
               p += "}"
            print("SELECT * FROM cypher('{}', $$ CREATE (:{} {}) $$ ) as (n agtype);".format(graph, file_name, p))
                
def convert_edge_csv(file_path, graph, from_type, to_type):
    file_name = os.path.splitext(os.path.basename(file_path))[0].lower()
    with open(file_path, 'r') as csvfile:
        reader = csv.reader(csvfile, delimiter=',')
        header = next(reader)
        for row in reader:
            p = ""
            for h in header:
                if (h.endswith("ID")):
                    continue;
                
                if p != "":
                    p += ","
                else:
                    p += "{"
                p += "{}:'{}'".format(h.lower(), row[header.index(h)].strip())
            
            if p != "":
               p += "}"
            
            print("SELECT * FROM cypher('{0}', $$ MATCH (a:{1}), (b:{2}) WHERE a.{1}_id = '{3}' AND "
                  "b.{2}_id = '{4}' CREATE (a)-[e:RELTYPE {5} ]->(b) RETURN e$$) as (e agtype);".format(graph, from_type, to_type, row[0].strip(), row[1].strip(), p))
def generate_graph_csv(directory, graph):
    print("------------------------------------------------")
    print("-- Create graph")
    print("SELECT create_graph('{}');".format(graph))
    print("------------------------------------------------")
    print("-- Create vertex")
    convert_vertex_csv(directory + "/POLICYHOLDER.csv", graph)
    convert_vertex_csv(directory + "/INCHARGE.csv", graph)
    convert_vertex_csv(directory + "/PATIENT.csv", graph)
    convert_vertex_csv(directory + "/CLAIM.csv", graph)
    convert_vertex_csv(directory + "/DISEASE.csv", graph)
    print("------------------------------------------------")
    print("-- Create edge")
    convert_edge_csv(directory + "/POLICYHOLDER_CONNECTION.csv", graph, 'policyholder','policyholder')
    convert_edge_csv(directory + "/INCHARGE_OF_CLAIM.csv", graph,'claim', 'incharge')
    convert_edge_csv(directory + "/CLAIM_SIMILARITY.csv", graph, 'claim','claim')
    convert_edge_csv(directory + "/POLICYHOLDER_OF_CLAIM.csv", graph,'claim', 'policyholder')
    convert_edge_csv(directory + "/INSURED_OF_CLAIM.csv", graph, 'claim','patient')
    convert_edge_csv(directory + "/HAS_DISEASE.csv", graph, 'patient','disease')
generate_graph_csv("analyzing-insurance-claims-using-ibm-db2-graph-master/data", "graph")

基于PolarDB的图分析：保险数据分析实践

前言