如何运行“postgres”命令（单用户）

Question

I have postgres installed on an ubuntu machine, and I am able to enter into the command line via something along the lines of:

$ sudo -u postgres psql
psql (10.15 (Ubuntu 10.15-0ubuntu0.18.04.1))
Type "help" for help.

postgres=#

And I can start/stop the server by doing something like:

$ sudo service postgresql
Usage: /etc/init.d/postgresql {start|stop|restart|reload|force-reload|status} [version ..]

Those both seem fine. However, I would like to run postgres in single-user mode to do a couple tests. On the postgres page it gives a few examples, such as:

To start a single-user mode server, use a command like
postgres --single -D /usr/local/pgsql/data other-options my_database

However, if I use the 'postgres' command, I just get an error saying I don't have that command:

$ postgres

Command 'postgres' not found, did you mean:

What do I need to install to run the 'postgres' command in order to enter single-user mode?

Answer 1

It is already installed, it is just not in your PATH, as it is not anticipated you would use it manually.

It is probably somewhere like "/usr/lib/postgresql/10/bin/postgres", or you can use locate or find to find it.

Answer 2

as you have not export the binary path that's why it's can't find your binary of postgres.

use this command:

/usr/lib/postgresql/10/bin/postgres --single -D /usr/local/pgsql/data other-options my_database

or,

you can export the path in bash

first open the bashrc with this command: nano ~/.bashrc

add this line in the end: PATH="/usr/lib/postgresql/10/bin/:$PATH"

run this command source ~/.bashrc

the just use postgres --single -D /usr/local/pgsql/data other-options my_database

you can also find where your binary is with this command: find /usr/lib -iname 'postgres'

Answer 3

Ubuntu has conf files spread over several places so:

/usr/lib/postgresql/13/bin/postgres --single -D /var/lib/postgresql/13/main -c "config_file=/etc/postgresql/13/main/postgresql.conf"