ArangoDB 图中集合的一致性是否有保证？

Question

Let say I have a collection node N and a edges collection E. Together , I created a graph G from N and E. In the document, Arango guarantee the consistency of graph G such as no dangling edges when nodes are deleted, etc. Does this consistency hold in situations such as:

1. Used Foxx, delete 1 node (Thus making edges have 1 null in the _from and _to)
2. Used Foxx, delete nodes using collection API (not using AQL)
3. Used AQL, delete directly in nodes/edges collection without traversal

I asked this question due to the fact that my query does return some null value of nodes and I would like to understand more about this topic for inspection.

Answer 1

Incoming and outgoing edges of a vertex are removed together with the vertex if you use the Graph API . You can use the General Graph module in Foxx and arangosh. Some drivers provide wrappers for this Graph API. The General Graph HTTP API is called Gharial .

If you remove vertices by other means, like a db or collection object in Foxx or arangosh, through the Web UI, with AQL or via HTTP endpoints for like DELETE /_api/document/{document-handle} , then you need to delete connected edges yourself or accept dangling edges.