Once PostgreSQL is installed on your Linux server, it's important to create the database installation before starting your PostgreSQL server. To create the database installation, use the following command:
                 [root@deep] /# su postgres
                 [postgres@deep /]$ initdb --pglib=/usr/lib/pgsql --pgdata=/var/lib/pgsql
               
               We are initializing the database system with username postgres uid=40.
               This user will own all the files and must also own the server process.
               
                 Creating Postgres database system directory /var/lib/pgsql/base
                 Creating template database in /var/lib/pgsql/base/template1
                 Creating global classes in /var/lib/pgsql/base
                 Adding template1 database to pg_database...
                 Vacuuming template1
                 Creating public pg_user view
                 Creating view pg_rules
                 Creating view pg_views
                 Creating view pg_tables
                 Creating view pg_indexes
                 Loading pg_description
               
                 [postgres@deep /]$ chmod 640 /var/lib/pgsql/pg_pwd
                 [postgres@deep /]$ exit
               
                 exit
               
                 [root@deep] /#
               
               The  --pglib command will specify where the library directory of PostgreSQL resides in the system, and the  --pgdata command will specify where the database files must reside 
               for this installation on Linux.
             
 
               
               Do not create the database installation as root! This would be a major security hole.
             
Please don't foreget to Cleanup later:
                 [root@deep] /# cd /var/tmp
                 [root@deep ]/tmp# rm -rf postgresql-version/ postgresql-version.tar.gz
               Remove the egcs-c++-version.i386.rpm package to save space.
                 [root@deep] /# rpm -e egcs-c++
               
                 The rm command will remove all the source files we have used to compile and install PostgreSQL. It will also remove the PostgreSQL compressed archive from the /var/tmp directory.
               
               The rpm -e command will remove the egcs-c++ package we installed to compile the PosgreSQL Server. Note that the egcs-c++ package is required only for compiling programs like 
               PostgreSQL and can be uninstalled safely after successful compilation of PostgreSQL.