There are 2+1 types of indexing in memgraph:

1. Vertices that have a specific label
2. Vertices that have a specific label and property, indexed by
3. +1: All of the vertices indexed by vertex id

Known issues

Indices probably doesn’t work well with lower isolation levels than snapshot

They are not using the ApplyDeltasForRead function from mvcc..hpp , but implement their own which is totally unaware of the isolation levels.