In An Introduction to Nebula Graph 2.0 Query Engine, I introduced how the query engine differs between V2.0 and V1.0 of Nebula Graph.

As shown in the preceding figure, you can see that when a query statement is sent from the client, how the query engine parses the statement, generates an AST, validates the AST, and then generates an execution plan. In this article, I will introduce more about the query engine through the new subgraph feature in Nebula Graph 2.0 and focus on the execution plan generation process, to help you understand the source code better.

Source: DZone