Andy Fan <zhihui.fan1...@gmail.com> wrote: > I just don't know why shm_mq is designed to single-reader & single-writer.
shm_mq was implemented as a part of infrastructure for parallel query processing. The leader backend launches multiple parallel workers and sets up a few queues to communicate with each. One queue is used to send request (query plan) to the worker, one queue is there to receive data from it, and I think there's one more queue to receive error messages. -- Antonin Houska https://www.cybertec-postgresql.com
