多个neo4j节点连接：“此查询在断开连接的模式之间构建笛卡尔积”(Multiple neo4j node join: “This query builds a cartesian product b

多个neo4j节点连接：“此查询在断开连接的模式之间构建笛卡尔积”(Multiple neo4j node join: “This query builds a cartesian product between disconnected patterns”)

我正在运行此查询：

MATCH (a:TEST:LOC1),(b:TEST_JOIN:LOC1),(c:TEST:LOC1) WHERE a._out = b._in and b._out = c._in and c._text = 'P' CREATE (a)-[r:TEST_JOIN]->(c)

它运行速度非常慢，执行计划说：“此查询在断开连接的模式之间构建笛卡尔积”

所有属性都已编入索引，我尝试过：

MATCH (c:TEST:LOC1) where c._text='P' with c MATCH (a:TEST:LOC1),(b:TEST_JOIN:LOC1) WHERE a._out = b._in and b._out = c._in CREATE (a)-[r:TEST_JOIN]->(c)

对不起，如果这是基本的。 有谁知道如何优化这个？ 提前谢谢了。

I'm running this query:

MATCH (a:TEST:LOC1),(b:TEST_JOIN:LOC1),(c:TEST:LOC1) WHERE a._out = b._in and b._out = c._in and c._text = 'P' CREATE (a)-[r:TEST_JOIN]->(c)

It runs very slowly, and the execution plan says: "This query builds a cartesian product between disconnected patterns"

All the properties are indexed and I have tried:

MATCH (c:TEST:LOC1) where c._text='P' with c MATCH (a:TEST:LOC1),(b:TEST_JOIN:LOC1) WHERE a._out = b._in and b._out = c._in CREATE (a)-[r:TEST_JOIN]->(c)

Sorry if this is basic. Does anyone know how to optimise this? Many thanks in advance.

最满意答案

我会尝试这个

MATCH (c:TEST:LOC1) where c._text='P' with c MATCH (b:TEST_JOIN:LOC1) where b._out = c._in with b, c Match (a:Test:LOC1) WHERE a._out = b._in with a, c CREATE (a)-[r:TEST_JOIN]->(c)

I would try this

MATCH (c:TEST:LOC1) where c._text='P' with c MATCH (b:TEST_JOIN:LOC1) where b._out = c._in with b, c Match (a:Test:LOC1) WHERE a._out = b._in with a, c CREATE (a)-[r:TEST_JOIN]->(c)