Change a parameter and reload (ALTER SYSTEM)

Command

ALTER SYSTEM SET work_mem = '64MB'; SELECT pg_reload_conf();

What it does

Writes the parameter to postgresql.auto.conf and reloads the configuration (effective immediately for parameters that do not require a restart).

When to use it

To persistently change parameters that can be applied by reload, such as work_mem and logging settings.

Caution

Some parameters such as shared_buffers and max_connections take effect only on restart, not reload; those with pg_settings.context = 'postmaster' require a restart.