Fixes #1582: rebind flag in apoc.periodic.iterate

[vga91]

Fixes #1582

• Added apoc.node.rebind / apoc.rel.rebind and apoc.any.rebind functions
• Added rebind config to apoc.periodic.iterate proc not to rebind manually the query if needed
• Added tests which fails without rebind via match (n) where id(n) = $id... or without apoc.<entity>.rebind function

[ncordon]

Thanks for PR man.

We decided core should not receive new functionality unless especifically approved. Feel free to either move the functionality to full or we can discuss with the whole team whether this is worthy of being added to core and breaking that policy.

[vga91]

I just moved the new functionality in full

[jexp]

@ncordon We should probably discuss this with Luisa.

Since 4.x this breaking change in neo4j is a big source of problems, as transaction state from nodes that are not rebound will leak into the original transaction and make it blow up.
As you can see from the issue it was already raised July 2020 and should have been long fixed.

[ncordon]

I don't understand why this is needed, nor we have added documentation in this PR, even though it's for 4.4 and the docs still live with the code.

Could you explain me what rebind is for, please?

[vga91]

I don't understand why this is needed, nor we have added documentation in this PR, even though it's for 4.4 and the docs still live with the code.

Could you explain me what rebind is for, please?

@ncordon
I added some docs and put an example to explain it.
For example, I could execute a CREATE (:Article {content: '1234'});,
and then:

CALL apoc.periodic.iterate('MATCH (art:Article) RETURN art',
'CREATE (node:Category) with art, node call apoc.create.relationship(art, "CATEGORY", {b: 1}, node) yield rel return rel', {});

In this case the procedure fails because the apoc.periodic.iterate open a new transaction, and inside this I create a node Category and try creating a new relationship, via org.neo4j.graphdb.Node.createRelationshipTo(),
that is in this case nodeWithLabelArticle.createRelationshipTo(nodeWithLabelCategory).

This fails (org.neo4j.graphdb.NotFoundException: Node[7] is deleted and cannot be used to create a relationship": 1)
because nodeWithLabelArticle was created outside the transaction and hold a reference to that, because of this createRelationship(..) does not recognize that node.

So we can rebind the node, via apoc.node.rebind or MATCH (n) WHERE id(n) = idNodeArticle ... to make sure that the node is recognized inside the new transaction.

[ncordon]

Thanks for the explanation 👍. I think this makes sense, but will hold off from approving given this is now out of Cypher's Surface responsibilities as long as it's in the extended part.

[Apollo9999]

The Code provided in the files are the Enhancement which Great features

[jexp]

Actually this is not the main issue, that also didn't work before, it's regular tx-visibility and I think that will also not be resolved by rebinding.

The issue that all the periodic-iterate tx-state is attached to the originating transaction if the node is not rebound to the new updating tx, which then leads to OOM issues. @vga91

[jexp]

we should have an explicit one for path, as otherwise we lose the type information and cypher doesn't recognize it as a path anymore