To create the variable in the environment of the server process you must first shut down the server, define the variable, initialize the data area, and finally restart the server. (See Section 3.6 and Section 3.3.) To set an environment variable, type


PGDATA2=/home/postgres/data
export PGDATA2

in Bourne shells, or

setenv PGDATA2 /home/postgres/data

in csh or tcsh. You have to make sure that this environment variable is always defined in the server environment, otherwise you won't be able to access that database. Therefore you probably want to set it in some sort of shell start-up file or server start-up script.

To create a data storage area in PGDATA2, ensure that the containing directory (here, /home/postgres) already exists and is writable by the user account that runs the server (see Section 3.1). Then from the command line, type


initlocation PGDATA2

Then you can restart the server.

To create a database within the new location, use the command

CREATE DATABASE name WITH LOCATION = 'location'
where location is the environment variable you used, PGDATA2 in this example. The createdb command has the option -D for this purpose.

Databases created in alternative locations can be accessed and dropped like any other database.