Understanding citus source code

[sai chandra mouli]

Hello everyone, 

I am a postgresql user who has been using citus for a few months for personal education purposes. Recently I became interested in understanding how citus is designed internally and hence started going through the source  code to understand how queries work in a distributed environment. However, it's  somewhat complex to me as I am new to this. Can anyone guide me on which methods are being triggered from which C files to (say) issue a Select command to read from a distributed table? From the distributed_planner.c to worker_partition_query_result.... What's the flow of methods involved in accomplishing a query as we see it on the output? Can anyone please help me on understanding citus internals? 

Thank You. 

Regards, 

Sai Chandra Mouli.