Reloading PostgreSQL after configuration changes

Question

I've made some changes to pg_hba.conf and I want them to take affect. I've found several places where people say that I can tell PostgreSQL to reload, but there are several different techniques listed, and none of them work for me yet.

The most authoritative reference I've found is for the pg_ctl command, but I'm not sure where my PGDATA folder is. I'll keep looking.

I'm running PostgreSQL 8.3 on Ubuntu 8.10.

Answer 1

You can check where your PGDATA is by connecting to pg, and issuing command:

show data_directory;

On ubuntu, it's usually /var/lib/postgresql/8.3/main/.

Also, you can: /etc/init.d/postgresql-8.3 reload

Answer 2

The following should do it for you:

sudo /etc/init.d/postgresql-8.3 reload

Answer 3

Though the original person asking the question implied he's running Ubuntu 8.10 many people, using later versions of Ubuntu might stumble here as well. And this might in fact work with 8.10 too. I dunno, I don't have any 8.10 installations to try it with..

Ok, lets cut to the point. So the cool "new" way of controlling services is to use the service command. So you can reload configs with the following command:

service postgresql-8.3 reload

naturally you need to have the proper rights so it is most likely required to prepend the command with something like sudo or su -c root like this:

sudo service postgresql-8.3 reload
or
su -c root 'service postgresql-8.3 reload'

P.S. It is suggested in the Ubuntu documentation that something relating to this new method had been done way back there with the release of 6.10, however if I've understood it correctly it had not been taken into more general use until 9.10.

Answer 4

I finally found a technique that works for me from this article. The command is:

sudo invoke-rc.d postgresql-8.3 reload

I'd still appreciate feedback on what the recommended technique is.

Answer 5

This will do the trick:

kill -HUP $(head -1 $PGDATA/postmaster.pid)