Compared with V1.0, Nebula Graph, a distributed graph database, has been significantly changed in V2.0. One of the most obvious changes is that in Nebula Graph 1.0, the code of the Query, Storage, and Meta modules are placed in one repository, while from Nebula Graph 2.0 onwards, these modules are placed in three repositories:
nebula-graph: Mainly contains the code of the Query module.
nebula-common: Mainly contains expression definitions, function definitions, and some public interfaces.
nebula-storage: Mainly contains the code of the Storage and Meta modules.
This article introduces the overall structure of the Query layer and uses an nGQL statement to describe how it is processed in the four main modules of the Query layer.