Neo4j加载csv的时间很长

大家好，Stackoverflow

我有一个简单的查询来加载csv，但浏览器需要很长时间才能加载，并且仍然显示加载符号

我的问题是：

LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED {rating:line.rating}]->(m) 
RETURN u, m, r

我看不出代码中有错误

ratings_small.csv有以下列：

用户ID电影ID分级时间戳

1312.51260759144

1 1029 3 1260759179

1106131260759182

112921260759185

1172 4 1260759205

有100004条记录

亲切问候,，

---

Anna

我相信你没有关于：User（name）和：Movie（movieId）的索引

执行以下两个查询，然后重试LOAD CSV命令，它将在几秒钟内导入该命令：

CREATE CONSTRAINT ON (u:User) ASSERT u.name IS UNIQUE;
CREATE CONSTRAINT ON (m:Movie) ASSERT m.moveId IS UNIQUE;

其次，我假设用户只对一部电影进行一次评分，因此不必对属性进行关系合并，您可以如下更改查询：

LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED]->(m)
SET r.rating = line.rating
RETURN u, m, r

USING PERIODIC COMMIT 2000
LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED]->(m)
SET r.rating = line.rating
RETURN u, m, r

为了避免Neo4j试图在一个事务中处理完整的CSV，您可以（为了避免内存问题）如下：

LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED]->(m)
SET r.rating = line.rating
RETURN u, m, r

USING PERIODIC COMMIT 2000
LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED]->(m)
SET r.rating = line.rating
RETURN u, m, r

最后，我怀疑您是否有任何应用程序，甚至Neo4j浏览器可以同时显示所有内容，因此我不会从LOAD CSV查询返回任何内容：

USING PERIODIC COMMIT 2000
LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED]->(m)
SET r.rating = line.rating

---

我相信你没有关于：User（name）和：Movie（movieId）的索引

执行以下两个查询，然后重试LOAD CSV命令，它将在几秒钟内导入该命令：

CREATE CONSTRAINT ON (u:User) ASSERT u.name IS UNIQUE;
CREATE CONSTRAINT ON (m:Movie) ASSERT m.moveId IS UNIQUE;

其次，我假设用户只对一部电影进行一次评分，因此不必对属性进行关系合并，您可以如下更改查询：

LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED]->(m)
SET r.rating = line.rating
RETURN u, m, r

USING PERIODIC COMMIT 2000
LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED]->(m)
SET r.rating = line.rating
RETURN u, m, r

为了避免Neo4j试图在一个事务中处理完整的CSV，您可以（为了避免内存问题）如下：

LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED]->(m)
SET r.rating = line.rating
RETURN u, m, r

USING PERIODIC COMMIT 2000
LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED]->(m)
SET r.rating = line.rating
RETURN u, m, r

最后，我怀疑您是否有任何应用程序，甚至Neo4j浏览器可以同时显示所有内容，因此我不会从LOAD CSV查询返回任何内容：

USING PERIODIC COMMIT 2000
LOAD CSV WITH HEADERS FROM "file:///ratings_small.csv" AS line 
WITH line MERGE (u:User{name:line.userId}) 
MERGE (m:Movie {movieId:line.movieId}) 
MERGE (u)-[r:RATED]->(m)
SET r.rating = line.rating

---

谢谢我添加了约束，现在我有了这个错误：Neo.DatabaseError.Statement.ExecutionFailed-java heap spaceI设置如下：dbms.memory.heap.initial\u size=5G dbms.memory.heap.max\u size=5G@Anna我编辑了答案.dbms.memory.pagecache.size=2G节点（：Movie，：User）一个接一个地加载正常。现在，我运行查询：------->使用定期提交2000加载CSV，标题来自“file:///ratings_small.csv“作为行与行匹配（u:User{userId:line.userId}），（m:Movie{movieId:line.movieId}）创建（u）-[r:RATED]->（m）SET r.rating=line.rating----------->它输出：执行在开放事务中使用定期提交的查询是不可能的，现在我有了这个错误：Neo.DatabaseError.Statement.ExecutionFailed-java heap spaceI设置如下：dbms.memory.heap.initial\u size=5G dbms.memory.heap.max\u size=5G@Anna我编辑了答案.dbms.memory.pagecache.size=2G节点（：Movie，：User）一个接一个地加载正常。现在，我运行查询：------->使用定期提交2000加载CSV，标题来自“file:///ratings_small.csv“作为行与行匹配（u:User{userId:line.userId}），（m:Movie{movieId:line.movieId}）创建（u）-[r:RATED]->（m）SET r.rating=line.rating----------->它输出：不可能在打开的事务中执行使用定期提交的查询