Neo4j持久查询要拆分/执行成较小的块? [英] Neo4j long lasting query to be split/executed in smaller chunks?

问题描述

我的import.csv创建了许多节点，并且合并创建了一个巨大的笛卡尔积，并在transaction timeout中运行，因为数据增长了很多.我目前将事务超时设置为1秒，因为所有其他查询都非常快，并且完成时间不应超过一秒.

My import.csv creates many nodes and merging creates a huge cartesian product and runs in a transaction timeout since the data has grown so much. I've currently set the transaction timeout to 1 second because every other query is very quick and is not supposed to take any longer than one second to finish.

是否有一种方法可以将较小的块拆分或执行此特定查询，以防止超时?

Is there a way to split or execute this specific query in smaller chunks to prevent a timeout?

不能选择在neo4j.conf中添加或禁用transaction timeout，因为neo4j服务需要重新启动配置中的所有更改.

Upping or disabling the transaction timeout in the neo4j.conf is not an option because the neo4j service needs a restart for every change made in the config.

查询击中了我的导入脚本的超时时间:

The query hitting the timeout from my import script:

 MATCH (l:NameLabel)
 MATCH (m:Movie {id: l.id,somevalue: l.somevalue})
 MERGE (m)-[:LABEL {path: l.path}]->(l);

节点数:1000电影，2500名称标签

Nodecounts: 1000 Movie, 2500 Namelabel

推荐答案

您可以尝试安装 APOC程序，并使用过程 apoc.periodic.commit .

You can try installing APOC Procedures and using the procedure apoc.periodic.commit.

call apoc.periodic.commit("
  MATCH (l:Namelabel)
  WHERE NOT (l)-[:LABEL]->(:Movie)
  WITH l LIMIT {limit}
  MATCH (m:Movie {id: l.id,somevalue: l.somevalue})
  MERGE (m)-[:LABEL {path: l.path}]->(l)
  RETURN count(*)
",{limit:1000})

下面的查询将在单独的事务中重复执行，直到返回0.

The below query will be executed repeatedly in separate transactions until it returns 0.

您可以更改{limit : 1000}的值.

注意:请记住要根据所使用的Neo4j的版本安装APOC程序.看看版本兼容性列表..

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