[master < T1026] Add vertex degree to index statistics

[Josipmrden]

Expanding extra information in ANALYZE GRAPH can be crucial for gaining insights on how to execute a particular query. One of such optimizations is counting information on vertex degrees. That way, supernodes don't need to be expanded when doing MERGE, but the expansion is done the other way around, so less edges need to be verified for checking if the edge exists when doing the merge.

[master < Task] PR

• Check, and update documentation if necessary (did not yet)
• Provide the full content or a guide for the final git message

To keep docs changelog up to date, one more thing to do:

• Write a release note here, including added/changed clause
  ANALYZE GRAPH query has been expanded with degree information for all the vertices to enhance MERGE optimizations on supernodes.
• Tag someone from docs team in the comments

[as51340]

Many things going on in the query planner. I think in general the feature makes a lot of sense. However I also think that we should make this always available to users not only when analyze graph is called since use cases are different, one is for optimizing indices, this is for generating query plan.

[Josipmrden]

@vpavicic (haven't still update the docs, will do that today/tomorrow)

[antoniofilipovic]

Looks good to me

[as51340]

Good job, I have few code comments, include them if you have time otherwise feel free to ignore, it won't break in either way

[vpavicic]

RN: The ANALYZE GRAPH; query now includes information about the degree of all
nodes to enhance the MERGE optimizations on supernodes.