On 28 June 2016 at 02:27, Akash Agrawal <aagra...@ncsu.edu> wrote: > Hi, > > I've created a background worker and I am using Postgresql-9.4. This > bgworker handles the job queue dynamically and goes to sleep if there is no > job to process within the next 1 hour. > > Now, I want to have a mechanism to wake the bgworker up in case if someone > adds a new job while the bgworker is in sleep mode. So to do it, I have > created a trigger which initially removes the existing background worker > and then registers a new one. >
Don't do that. Instead, set the background worker's process latch, which you can find in the PGPROC array. There are a variety of examples of how to set latches in the sources. > > I am retrieving the pid from pg_Stat_activity. The maximum number of > background worker that can run simultaneously is equal to 8. I think even > if I call pg_terminate_backend the metadata of the background worker is not > being deleted > Correct. Unless you register it as a dynamic bgworker with no automatic restart, it'll get restarted when it exits uncleanly. Have the worker call proc_exit(0) if you want it not to be restarted. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
