Stopping the server quickly

There are different modes available to stop the PostgreSQL server. Here we will talk about the mode in which we can stop the server quickly.

Getting ready

The pg_ctl command is used in combination with the stop option in order to stop the PostgreSQL server.

How to do it...

We can use the following command to stop the server quickly on Red Hat-based Linux distributions and other Unix-based systems:

pg_ctl -D /var/lib/pgsql/9.6/data -m fast stop

Here, /var/lib/pgsql/9.6/data is the location of the data directory.

How it works...

The -m fast option must be used in order to shut down as quickly as possible. In case of a normal shutdown, PostgreSQL will wait for all users to finish their transactions before halting and on a busy system this can sometimes take a very long time.

While initiating a fast stop with the -m fast option of the pg_ctl command, all the users will have their transactions aborted and all connections are disconnected. However, this is a clean shutdown because all the active transactions are aborted followed, by a system checkpoint before the server closes.

Also, it will verify various checks, such as whether PostgreSQL has started in a single user mode or whether the cluster is running in backup mode while shutting down the database, and will interact with the user by throwing the required notification messages.