On Sun, Dec 11, 2016 at 2:39 PM, Qiu Xiafei <qiuxiafei@xxxxxxxxx> wrote: > Because of the one-backend-per-session concept of PG, I think I should bind > one my DSL session to one bg worker only. It seems work. But is there a way > to launch a bg worker when a new session starts, just like pg's > per-session-backend do? Is it possible to run a bg worker for incoming > sessions and to launch a new bg worker to handle the session when it comes? There is the concept of dynamic background workers in Postgres. That's what for example parallel query uses. At planning a number of workers thought as suited is selected, and then spawned dynamically at execution, at the limit defined by max_worker_processes though. Have a look at worker_spi in the code tree, which is a module that does present a way to spawn workers dynamically. This infrastructure could allow for example anybody to re-create what autovacuum does with a launcher process and workers created depending on what needs to be cleaned up per database as a plugin. -- Michael -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
