pg_ctl:tldr:92f96

This command is used to send a reload signal to a running PostgreSQL database cluster.

Here's what each part of the command means:

• pg_ctl: This is the command-line utility used to control PostgreSQL database clusters.
• -D ${data_directory}: This specifies the path to the data directory of the PostgreSQL cluster. ${data_directory} is typically replaced with the actual path to the data directory.
• reload: This is the argument passed to pg_ctl that tells it to send a reload signal to the PostgreSQL cluster.

When the pg_ctl command is executed with the -D ${data_directory} reload arguments, it will locate and connect to the running PostgreSQL cluster using the specified data directory and instruct it to reload its configuration files. This can be useful after making changes to the configuration files (e.g., postgresql.conf) to apply those changes without restarting the entire PostgreSQL cluster.