Reloading server configuration

In this recipe, we will talk about the command that can be used to reload the server configuration and its parameters.

Getting ready

If any of the server parameters come into effect after reloading the server configuration files, such as postgresql.conf, then we need to reload the server configuration using the reload option of the pg_ctl command.

How to do it...

We can use the following command to reload the server configuration on Red Hat-based Linux and Unix distributions:

pg_ctl -D /var/lib/pgsql/9.6/data reload

You can also reload the configuration using the pg_reload_conf function while still being connected to PostgreSQL .The usage of the pg_reload_conf function is mentioned as follows:

postgres=# select pg_reload_conf();

How it works...

The reload mode of the pg_ctl command is used to send the postgres process a SIGHUP signal, which in turn causes it to reload its configuration files such as postgresql.conf and pg_hba.conf. The benefit of this mode is that it allows the configuration changes to be reloaded without requiring a complete restart of the PostgreSQL server to come into effect.

In this mode, PostgreSQL will send a SIGHUP signal to each child process, including the utility processes such as autovacuum, bgwriter, stats collector, and so on, to get the new settings from the latest configuration settings.