Neo4j的实施意见 [英] Neo4j implementing comments

问题描述

在我的春节，启动/ Neo4j的应用程序，我有Neo4j的节点的一棵大树，现在我想实现多层次的意见对各节点的。

In my Spring Boot/Neo4j application I have a big tree of Neo4j nodes and now I would like to implement hierarchical comments for each of these node.

现在，我想在那里这些评论必须放置在......在Neo4j的数据库或其他外部RDBMS / NoSQL的存储空间。

Right now I'm thinking of where these comments must be placed in... In Neo4j database or in some other external RDBMS/NoSQL storage.

为什么我想它 - 因为现在我面临着（与许多关系到其他节点的节点组合）去除沉重的Neo4j节点的问题我有限的知识Cypher支架..和我不解决这个问题现在的问题..所以引入新的注释节点可以完全杀死我的系统。

Why I'm thinking about it - because of my limited Cypher knowledge right now I'm faced with the problem of removing heavy Neo4j nodes(composite nodes with many relationships to other nodes).. and I can't fix this issue now.. so introducing new Comment nodes can totally kill my system.

所以，你怎么想，我应该尝试解决问题，删除或实施一些外部数据存储评论？

So what do you think, should I try to fix the delete issue or implement Comments in some external data storage ?

更新时间：

这是我的慢删除查询：

MATCH (d:Decision) 
WHERE id(d) IN {decisionsIds} 
OPTIONAL MATCH (d)-[r]-(t) 
DELETE d, r 
WITH t, r WHERE NOT (id(t) IN {decisionsIds}) 
OPTIONAL MATCH (t)-[r2:VOTED_ON|:CREATED_BY|:VOTED_FOR]-()-[r3:CONTAINS]-(t2) WHERE r2 <> r 
WITH t, r2, t2, r3 
WHERE none(x in labels(t) 
WHERE x in ['User', 'Decision']) 
DELETE t, r2, t2, r3

现在这个查询的工作很长一段时间，所以我不敢为了不彻底杀灭性能增加新的实体决策节点。

Right now this query works long time so I afraid to add new entities to Decision node in order to not kill the performance completely.

时的任何方式来优化这个查询？

Is any way to optimize this query ?

推荐答案

如果没有一个数据库，这是一个小的优化企图，不知道这是否会有所帮助。

Without a db this is an attempt for a small optimization, not sure if it helps.

这将是也是很好的了解更多的领域模型和元素之间的基数（如 D 和 T ）

It would be also good to know more about the domain model and the cardinalities between the element (e.g. between d and t)

MATCH (d:Decision) WHERE id(d) IN {decisionsIds} 
OPTIONAL MATCH (d)-[r]-(t) 
DELETE d, r 
WITH t, collect(r) as rels 
  WHERE NOT (id(t) IN {decisionsIds}) AND NOT t:User OR t:Decision
OPTIONAL MATCH (t)-[r2:VOTED_ON|:CREATED_BY|:VOTED_FOR]-(t1)
  WHERE NOT (r2 in rels)
OPTIONAL MATCH (t1)-[r3:CONTAINS]-(t2) 
DELETE t, r2, t2, r3;

更新

你的数据库的测试，工作pretty，很好。关于你的说法，我不知道哪些是违反

Update

Tested with your DB, worked pretty, well. Regarding your assertions, I'm not sure which ones are violated.

export decisionsIds=[332,336,335,334,333,340,339,338,337,344,343,342,341] 

MATCH (d:Decision) WHERE id(d) IN {decisionsIds} 
OPTIONAL MATCH (d)-[r]-(t) 
DELETE d, r 
WITH t, collect(r) as rels 
  WHERE NOT (t:User OR t:Decision) AND NOT (id(t) IN {decisionsIds})
OPTIONAL MATCH (t)-[r2:VOTED_ON|:CREATED_BY|:VOTED_FOR|:CONTAINS]-(t1)
  WHERE NOT (r2 in rels)
DELETE t, r2
WITH t1
OPTIONAL MATCH (t1)-[:CONTAINS]-(t2) 
// will be detach delete in 2.3
FOREACH ( p IN (t2)--() | DELETE head(rels(p)))
DELETE t2;

+-------------------+
| No data returned. |
+-------------------+
Nodes deleted: 362
Relationships deleted: 723
340 ms

您可以找到你这样的问题的节点：

You can find your offending node like this:

neo4j-sh (?)$ match (n)-[r]-() where id(n) = 86715 return labels(n),n,r;
+----------------------------------------------------------------------------------------------------------------------------------+
| labels(n)                  | n                                                                            | r                    |
+----------------------------------------------------------------------------------------------------------------------------------+
| ["VoteGroup","_VoteGroup"] | Node[86715]{createDate:"1443124989049",avgVotesWeight:5.0,totalVotesCount:1} | :CONTAINS[173172]{}  |
| ["VoteGroup","_VoteGroup"] | Node[86715]{createDate:"1443124989049",avgVotesWeight:5.0,totalVotesCount:1} | :VOTED_ON[173169]{}  |
| ["VoteGroup","_VoteGroup"] | Node[86715]{createDate:"1443124989049",avgVotesWeight:5.0,totalVotesCount:1} | :VOTED_FOR[173170]{} |
+----------------------------------------------------------------------------------------------------------------------------------+

如果你想看到的是感动了所有的数据/将通过这个查询被删除使用：

If you want to see all data that is touched / would be deleted by this query use this:

MATCH (d:Decision) WHERE id(d) IN {decisionsIds} 
OPTIONAL MATCH (d)-[r]-(t) 
WITH t, collect(r) as rels 
  WHERE NOT (t:User OR t:Decision) AND NOT (id(t) IN {decisionsIds})
OPTIONAL MATCH (t)-[r2:VOTED_ON|:CREATED_BY|:VOTED_FOR|:CONTAINS]-(t1)
  WHERE NOT (r2 in rels)
OPTIONAL MATCH (t1)-[:CONTAINS]-(t2)
RETURN *;

然后你可以找到你的问题的节点的结果，并确保已删除周围的一切（每REL型）。

Then you can find your offending nodes in the result, and make sure that you deleted everything (every rel-type) around them.

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