FETCH EDGE for wildcard of rank

[wey-gu]

Is your feature request related to a problem? Please describe.

Get all ranked edges with given src/dst.

Describe the solution you'd like

implement getEdges() interface to support scan all ranks, I see this isn't that ideally efficient due to rank key is between srcVID, type, and dstVID rather than after dstVID(it will be faster to scan), but it's still faster than the current plan being done through MATCH(which started from vertex and Traverse)*.

*: Without support of fetch edge for all ranks, the best way to get this is:

explain match (m:t1)-[e:e1]->(n:t1) WHERE id(m)=="10" AND id(n)=="11" return e

Describe alternatives you've considered

Additional context

• https://discuss.nebula-graph.io/t/how-to-create-a-list-datatype-in-nebula/1185/5?u=wey
• also it's discussed offline in wechat groups before

[akhilravuri-tul-scm]

When we can expect this feature in production?

I know It's very early just wanted to know the estimated timeline.