On 25th of October 2018, Michael Paquier committed patch:
Add pg_promote function This function is able to promote a standby with this new SQL-callable function. Execution access can be granted to non-superusers so that failover tools can observe the principle of least privilege. Catalog version is bumped. Author: Laurenz Albe Discussion: https://postgr.es/m/.camel@cybertec.at
Continue reading Waiting for PostgreSQL 12 – Add pg_promote function