Some of the steps required to use Postgres can be performed by any Postgres user, and some must be done by the site database administrator. This site administrator is the person who installed the software, created the database directories and started the postmaster process. This person does not have to be the Unix superuser ("root") or the computer system administrator; a person can install and use Postgres without any special accounts or privileges.
If you are installing Postgres yourself, then refer to the Administrator's Guide for instructions on installation, and return to this guide when the installation is complete.
Throughout this manual, any examples that begin with the character "%" are commands that should be typed at the Unix shell prompt. Examples that begin with the character "*" are commands in the Postgres query language, Postgres SQL.
This section discusses how to set up your own environment so that you can use frontend applications. We assume Postgres has already been successfully installed and started; refer to the Administrator's Guide and the installation notes for how to install Postgres.
Postgres is a client/server application. As a user, you only need access to the client portions of the installation (an example of a client application is the interactive monitor psql). For simplicity, we will assume that Postgres has been installed in the directory /usr/local/pgsql. Therefore, wherever you see the directory /usr/local/pgsql you should substitute the name of the directory where Postgres is actually installed. All Postgres commands are installed in the directory /usr/local/pgsql/bin. Therefore, you should add this directory to your shell command path. If you use a variant of the Berkeley C shell, such as csh or tcsh, you would add
% set path = ( /usr/local/pgsql/bin path )
    
    in the .login file in your home directory.
    If you use
    a  variant  of  the  Bourne  shell, such as sh, ksh, or
    bash, then you would add
    % PATH=/usr/local/pgsql/bin:$PATH
% export PATH
    
    to the .profile file in your home directory.
    From now on, we will assume that  you  have  added  the
    Postgres  bin  directory to your path.
    In addition, we
    will make frequent reference to "setting a shell  
     variable"  or  "setting an environment
     variable" throughout
    this document.  If you did  not  fully  understand  the
    last  paragraph  on  modifying  your  search  path, you
    should consult the Unix manual pages that describe your
    shell before going any further.
   If your site administrator has not set things up in the default way, you may have some more work to do. For example, if the database server machine is a remote machine, you will need to set the PGHOST environment variable to the name of the database server machine. The environment variable PGPORT may also have to be set. The bottom line is this: if you try to start an application program and it complains that it cannot connect to the postmaster, you should immediately consult your site administrator to make sure that your environment is properly set up.