Restarting the server quickly
Some of the database server parameters require you to stop and start the server again fully. Doing this as quickly as possible can be very important in some cases. The best time to do this is usually a quiet time, with lots of planning, testing, and forethought. Sometimes, not everything goes according to plan.
How to do it…
Many of the recipes in this chapter are presented in two forms: one with systemd
 and one without. This may look repetitive or boring, but it's unavoidable because introducing a new system does not automatically eliminate all existing alternatives or migrate old installations to new ones.
As we mentioned previously, you can find further systemd
 details, including details on service unit names, in the previous recipe, Starting the database server manually.
A PostgreSQL server that's managed by systemd
 can be restarted in fast mode by issuing the following...