What is the "NODE RELATIONSHIP GROUP DELETE" resourceType?

[ivan_ivanov]

Hello,
My name is Ivan and while debugging deadlock issues I've come upon "NODE_RELATIONSHIP_GROUP_DELETE" resource type when calling:

CALL dbms.listActiveLocks(queryId)

I see that the resourceId is an <id> of a node, however I can neither find any explanation of what does this resourceType mean nor I can deduce what it's supposed to be?

Is there a documentation somewhere explaining all of the resource types ? I am interested in "DEGREES" resourceType as well.

[andrew_bowman]

Hello, this has to do with changes made to the structure of a node's relationships when it crosses the configured threshold for dense nodes (defaults are set at 50 relationships to be considered dense). Relationship groups are part of a relationship chain locks feature introduced with Neo4j 4.3.x, and aim to reduce the locking resources needed when performing relationship additions or removals on dense nodes.

We have a blog entry about this here:

https://neo4j.com/developer-blog/relationship-chain-locks-dont-block-the-rock/