作者:瀚高PG实验室 (Highgo PG Lab)- 亨特少校
参考文章:PostgreSQL: Documentation: 10: Chapter 52. Frontend/Backend Protocol
In order to serve multiple clients efficiently, the server launches a new “backend” process for each client.
In the current implementation, a new child process is created immediately after an incoming connection is detected.
This is transparent to the protocol, however. For purposes of the protocol, the terms “backend” and “server” are interchangeable;
likewise “frontend” and “client” are interchangeable.