queue_classic adapter for Active Job
queue_classic provides a simple interface to a PostgreSQL-backed message queue. queue_classic specializes in concurrent locking and minimizing database load while providing a simple, intuitive developer experience. queue_classic assumes that you are already using PostgreSQL in your production environment and that adding another dependency (e.g. redis, beanstalkd, 0mq) is undesirable.
Read more about queue_classic here.
To use queue_classic set the queue_adapter config to :queue_classic.
Rails.application.config.active_job.queue_adapter = :queue_classic